| Monday, January 28 |
| Future Astro Oscar Henriquez is born in LaGuaira, Venezuela. |
| Saturday, March 9 |
| Future Astro Wayne Franklin is born in Wilmington, DE. |
| Monday, March 11 |
| Future Astro Bobby Abreu is born in Aragua, Venezuela. |
| Thursday, April 4 |
| » Major-league debuts: Jim Sundberg (Rangers) |
| Friday, April 5 |
| » Lost to Giants (1-0), 5-1 | Candlestick Park (0-1) | 0-1 | |
| » W: Tom Bradley (1-0) L: Dave Roberts (0-1) | Second | 1 out |
| Saturday, April 6 |
| » Lost to Giants (2-0), 3-2 | Candlestick Park (0-2) | 0-2 | Lost 2 |
| » W: Mike Caldwell (1-0) L: Tom Griffin (0-1) S: Randy Moffitt (1) | Second | 2 out |
| » Major-league debuts: Larry Milbourne (Astros) |
| Sunday, April 7 |
| » Lost to Giants (3-0), 8-4 | Candlestick Park (0-3) | 0-3 | Lost 3 |
| » W: Jim Willoughby (1-0) L: Claude Osteen (0-1) S: Jim Barr (1) | Fourth | 3 out |
| Tuesday, April 9 |
| » Defeated Padres (0-4), 9-5 | San Diego/Jack Murphy Stadium (1-0) | 1-3 | |
| » W: Larry Dierker (1-0) L: Steve Arlin (0-1) | Fourth | 2½ out |
| Wednesday, April 10 |
| » Defeated Padres (0-5), 9-1 | San Diego/Jack Murphy Stadium (2-0) | 2-3 | Won 2 |
| » W: Dave Roberts (1-1) L: Bill Greif (0-2) | Third | 2½ out |
| Thursday, April 11 |
| » Defeated Padres (0-6), 9-1 | San Diego/Jack Murphy Stadium (3-0) | 3-3 | Won 3 |
| » W: Tom Griffin (1-1) L: Randy Jones (0-2) | Third | 2 out |
| Friday, April 12 |
| » Defeated Dodgers (5-3), 5-3 | Astrodome (1-0) | 4-3 | Won 4 |
| » W: Claude Osteen (1-1) L: Al Downing (0-2) S: Ken Forsch (1) | Third | 1 out |
| Saturday, April 13 |
| » Lost to Dodgers (6-3), 6-3 | Astrodome (1-1) | 4-4 | |
| » W: Don Sutton (3-0) L: Don Wilson (0-1) | Third | 2 out |
| Sunday, April 14 |
| » Lost to Dodgers (7-3), 7-2 | Astrodome (1-2) | 4-5 | Lost 2 |
| » W: Tommy John (3-0) L: Dave Roberts (1-2) | Fourth | 2½ out |
| Monday, April 15 |
| » Defeated Giants (6-4), 3-1 | Astrodome (2-2) | 5-5 | |
| » W: Larry Dierker (2-0) L: Mike Caldwell (2-1) | Fourth | 2 out |
| Tuesday, April 16 |
| » Defeated Giants (6-5), 4-0 | Astrodome (3-2) | 6-5 | Won 2 |
| » W: Tom Griffin (2-1) L: Jim Willoughby (1-2) | Second | 2 out |
| Wednesday, April 17 |
| » Defeated Giants (6-6), 3-2 | Astrodome (4-2) | 7-5 | Won 3 |
| » W: Claude Osteen (2-1) L: John D'Acquisto (2-1) S: Ken Forsch (2) | Second | 2 out |
| Thursday, April 18 |
| » Lost to Giants (7-6), 5-2 | Astrodome (4-3) | 7-6 | |
| » W: Tom Bradley (2-1) L: Doug Konieczny (0-1) | Second | 2½ out |
| Friday, April 19 |
| » Defeated Braves (7-7), 8-2 | Astrodome (5-3) | 8-6 | |
| » W: Dave Roberts (2-2) L: Phil Niekro (3-1) | Second | 1½ out |
| Saturday, April 20 |
| » Lost to Braves (8-7), 4-3 | Astrodome (5-4) | 8-7 | |
| » W: Ron Reed (3-1) L: Ken Forsch (0-1) | Second | 2½ out |
| Sunday, April 21 |
| » Defeated Braves (8-8), 4-3 | Astrodome (6-4) | 9-7 | |
| » W: Jerry Johnson (1-0) L: Danny Frisella (0-1) | Second | 1½ out |
| Monday, April 22 |
| » Defeated Braves (8-9), 7-0 | Astrodome (7-4) | 10-7 | Won 2 |
| » W: Claude Osteen (3-1) L: Roric Harrison (1-3) | Second | 1 out |
| Tuesday, April 23 |
| » Lost to Cardinals (10-7), 8-2 | Busch Stadium II (0-1) | 10-8 | |
| » W: Sonny Siebert (2-1) L: Doug Konieczny (0-2) | Second | 2 out |
| Wednesday, April 24 |
| » Defeated Cardinals (10-8), 9-4 | Busch Stadium II (1-1) | 11-8 | |
| » W: Dave Roberts (3-2) L: Lynn McGlothen (2-1) | Second | 2 out |
| Friday, April 26 |
| » Lost to Pirates (5-11), 4-3 | Three Rivers Stadium (0-1) | 11-9 | |
| » W: Dave Giusti (1-1) L: Fred Scherman (0-1) | Third | 3½ out |
| » Major-league debuts: Mario Mendoza (Pirates) |
| Saturday, April 27 |
| » Defeated Pirates (5-12), 10-7 | Three Rivers Stadium (1-1) | 12-9 | |
| » W: Tom Griffin (3-1) L: Bob Moose (1-3) | Second | 3½ out |
| » Major-league debuts: Jim Sadowski (Pirates) |
| Sunday, April 28 |
| » Lost to Pirates (6-12), 7-3 | Three Rivers Stadium (1-2) | 12-10 | |
| » W: Ken Brett (2-1) L: Claude Osteen (3-2) S: Dave Giusti (2) | Second | 4½ out |
| Monday, April 29 |
| » Defeated Cubs (7-10), 18-2 | Astrodome (8-4) | 13-10 | |
| » W: Dave Roberts (4-2) L: Bill Bonham (1-4) | Second | 4½ out |
| » Major-league debuts: Jim Todd (Cubs) |
| Tuesday, April 30 |
| » Defeated Cubs (7-11), 4-2 | Astrodome (9-4) | 14-10 | Won 2 |
| » W: Ken Forsch (1-1) L: Horacio Pina (1-2) | Second | 3½ out |
| Wednesday, May 1 |
| » Defeated Cubs (7-12), 11-7 | Astrodome (10-4) | 15-10 | Won 3 |
| » W: Don Wilson (1-1) L: Rick Reuschel (0-1) | Second | 3½ out |
| Friday, May 3 |
| » Defeated Cardinals (13-11), 4-1 | Astrodome (11-4) | 16-10 | Won 4 |
| » W: Claude Osteen (4-2) L: Alan Foster (1-2) | Second | 2½ out |
| Saturday, May 4 |
| » Defeated Cardinals (13-12), 3-2 | Astrodome (12-4) | 17-10 | Won 5 |
| » W: Dave Roberts (5-2) L: Sonny Siebert (2-2) S: Ken Forsch (3) | Second | 1½ out |
| Sunday, May 5 |
| » Lost to Cardinals (14-12), 3-1 | Astrodome (12-5) | 17-11 | |
| » W: Bob Gibson (2-2) L: Larry Dierker (2-1) | Second | 1½ out |
| Tuesday, May 7 |
| » Defeated Pirates (8-15), 2-1 | Astrodome (13-5) | 18-11 | |
| » W: Tom Griffin (4-1) L: Dock Ellis (1-2) | Second | 1 out |
| Wednesday, May 8 |
| » Defeated Pirates (8-16), 8-6 | Astrodome (14-5) | 19-11 | Won 2 |
| » W: Mike Nagy (1-0) L: Jim Sadowski (0-1) | Second | 1 out |
| Thursday, May 9 |
| » Lost to Pirates (9-16), 4-1 | Astrodome (14-6) | 19-12 | |
| » W: Jim Rooker (2-2) L: Dave Roberts (5-3) | Second | 2 out |
| Friday, May 10 |
| » Lost to Reds (13-13), 2-1 | Riverfront Stadium (0-1) | 19-13 | Lost 2 |
| » W: Jack Billingham (5-1) L: Larry Dierker (2-2) | Second | 3 out |
| Saturday, May 11 |
| » Defeated Reds (13-14), 4-2 | Riverfront Stadium (1-1) | 20-13 | |
| » W: Tom Griffin (5-1) L: Roger Nelson (1-3) | Second | 3 out |
| Sunday, May 12 |
| » Lost to Reds (14-14), 5-0 | Riverfront Stadium (1-2) | 20-14 | |
| » W: Fred Norman (2-3) L: Claude Osteen (4-3) | Second | 4½ out |
| » Lost to Reds (15-14), 4-2 | Riverfront Stadium (1-3) | 20-15 | Lost 2 |
| » W: Clay Kirby (2-3) L: Don Wilson (1-2) | Second | 4½ out |
| Monday, May 13 |
| » Lost to Dodgers (24-9), 8-4 | Dodger Stadium (0-1) | 20-16 | Lost 3 |
| » W: Andy Messersmith (4-0) L: Dave Roberts (5-4) | Second | 5½ out |
| Tuesday, May 14 |
| » Lost to Dodgers (25-9), 1-0 | Dodger Stadium (0-2) | 20-17 | Lost 4 |
| » W: Don Sutton (6-2) L: Larry Dierker (2-3) | Third | 6½ out |
| Wednesday, May 15 |
| » Lost to Dodgers (26-9), 11-7 | Dodger Stadium (0-3) | 20-18 | Lost 5 |
| » W: Charlie Hough (3-1) L: Mike Nagy (1-1) S: Mike Marshall (3) | Fourth | 8½ out |
| » Lost to Dodgers (27-9), 10-2 | Dodger Stadium (0-4) | 20-19 | Lost 6 |
| » W: Doug Rau (3-1) L: Doug Konieczny (0-3) | Fourth | 8½ out |
| Friday, May 17 |
| » Lost to Reds (18-15), 4-2 | Astrodome (14-7) | 20-20 | Lost 7 |
| » W: Fred Norman (3-3) L: Claude Osteen (4-4) S: Clay Carroll (1) | Fifth | 8½ out |
| Saturday, May 18 |
| » Lost to Reds (19-15), 7-6 | Astrodome (14-8) | 20-21 | Lost 8 |
| » W: Pedro Borbon (2-1) L: Fred Scherman (0-2) | Fourth | 9½ out |
| Sunday, May 19 |
| » Lost to Reds (20-15), 7-1 | Astrodome (14-9) | 20-22 | Lost 9 |
| » W: Don Gullett (4-3) L: Dave Roberts (5-5) | Fifth | 9½ out |
| Monday, May 20 |
| » Lost to Padres (17-27), 8-6 | Astrodome (14-10) | 20-23 | Lost 10 |
| » W: Vicente Romo (1-1) L: Fred Scherman (0-3) | Fifth | 10½ out |
| Tuesday, May 21 |
| » Defeated Padres (17-28), 5-4 | Astrodome (15-10) | 21-23 | |
| » W: Tom Griffin (6-1) L: Dan Spillner (0-1) S: Fred Scherman (1) | Fifth | 10½ out |
| » Major-league debuts: Dan Spillner (Padres) |
| Wednesday, May 22 |
| » Defeated Padres (17-29), 5-1 | Astrodome (16-10) | 22-23 | Won 2 |
| » W: Claude Osteen (5-4) L: Randy Jones (3-7) | Fifth | 10½ out |
| Friday, May 24 |
| » Lost to Braves (23-21), 3-0 | Atlanta-Fulton County Stadium (0-1) | 22-24 | |
| » W: Buzz Capra (3-2) L: Don Wilson (1-3) | Fifth | 10 out |
| Saturday, May 25 |
| » Defeated Braves (23-22), 5-1 | Atlanta-Fulton County Stadium (1-1) | 23-24 | |
| » W: Ken Forsch (2-1) L: Carl Morton (6-4) | Fifth | 10 out |
| Tuesday, May 28 |
| » Defeated Expos (20-18), 8-4 | Parc Jarry (1-0) | 24-24 | Won 2 |
| » W: Mike Cosgrove (1-0) L: Steve Rogers (7-3) | Fifth | 10 out |
| Wednesday, May 29 |
| » Defeated Expos (20-19), 5-3 | Parc Jarry (2-0) | 25-24 | Won 3 |
| » W: Ken Forsch (3-1) L: Tom Walker (1-1) | Fifth | 10 out |
| Thursday, May 30 |
| » Defeated Expos (20-20), 4-3 | Parc Jarry (3-0) | 26-24 | Won 4 |
| » W: Jerry Johnson (2-0) L: Chuck Taylor (1-1) S: Fred Scherman (2) | Fourth | 9½ out |
| Friday, May 31 |
| » Defeated Mets (20-28), 7-1 | Shea Stadium (1-0) | 27-24 | Won 5 |
| » W: Don Wilson (2-3) L: Jerry Koosman (5-3) S: Fred Scherman (3) | Fourth | 9½ out |
| Saturday, June 1 |
| » Lost to Mets (21-28), 3-1 | Shea Stadium (1-1) | 27-25 | |
| » W: Tom Seaver (3-5) L: Dave Roberts (5-6) | Fourth | 10½ out |
| Tuesday, June 4 |
| » Lost to Expos (22-21), 5-0 | Astrodome (16-11) | 27-26 | Lost 2 |
| » W: Ernie McAnally (4-4) L: Tom Griffin (6-2) | Fifth | 11 out |
| Wednesday, June 5 |
| » Lost to Expos (23-21), 8-3 | Astrodome (16-12) | 27-27 | Lost 3 |
| » W: Mike Torrez (5-4) L: Claude Osteen (5-5) | Fourth | 12 out |
| Thursday, June 6 |
| » Defeated Expos (23-22), 4-0 | Astrodome (17-12) | 28-27 | |
| » W: Larry Dierker (3-3) L: Steve Renko (3-6) | Fifth | 12 out |
| Friday, June 7 |
| » Defeated Mets (22-31), 1-0 | Astrodome (18-12) | 29-27 | Won 2 |
| » W: Don Wilson (3-3) L: Harry Parker (1-4) | Fourth | 12 out |
| Saturday, June 8 |
| » Lost to Mets (23-31), 6-5 | Astrodome (18-13) | 29-28 | |
| » W: Ray Sadecki (4-2) L: Jim York (0-1) | Fourth | 12 out |
| Sunday, June 9 |
| » Defeated Mets (23-32), 11-1 | Astrodome (19-13) | 30-28 | |
| » W: Tom Griffin (7-2) L: Jerry Koosman (5-4) | Fourth | 12 out |
| Monday, June 10 |
| » Lost to Phillies (31-26), 12-0 | Astrodome (19-14) | 30-29 | |
| » W: Jim Lonborg (7-5) L: Claude Osteen (5-6) | Fourth | 12 out |
| Tuesday, June 11 |
| » Defeated Phillies (31-27), 10-1 | Astrodome (20-14) | 31-29 | |
| » W: Larry Dierker (4-3) L: Dick Ruthven (2-3) | Fourth | 11 out |
| Wednesday, June 12 |
| » Lost to Phillies (32-27), 3-0 | Astrodome (20-15) | 31-30 | |
| » W: Steve Carlton (9-4) L: Don Wilson (3-4) | Fourth | 11 out |
| Friday, June 14 |
| » Lost to Cubs (24-31), 10-7 | Wrigley Field (0-1) | 31-31 | Lost 2 |
| » W: Jim Todd (1-0) L: Dave Roberts (5-7) | Fourth | 12 out |
| » Major-league debuts: Steve Swisher (Cubs) |
| Saturday, June 15 |
| » Defeated Cubs (24-32), 8-7 | Wrigley Field (1-1) | 32-31 | |
| » W: Fred Scherman (1-3) L: Horacio Pina (3-4) S: Dave Roberts (1) | Fourth | 11 out |
| Sunday, June 16 |
| » Lost to Cubs (25-32), 2-1 | Wrigley Field (1-2) | 32-32 | |
| » W: Burt Hooton (3-5) L: Ken Forsch (3-2) | Fourth | 12 out |
| Monday, June 17 |
| » Lost to Phillies (34-29), 7-5 | Veteran's Stadium (0-1) | 32-33 | Lost 2 |
| » W: Wayne Twitchell (1-1) L: Claude Osteen (5-7) | Fourth | 12 out |
| Tuesday, June 18 |
| » Defeated Phillies (34-30), 1-0 | Veteran's Stadium (1-1) | 33-33 | |
| » W: Mike Cosgrove (2-0) L: Ron Schueler (3-8) | Fourth | 11 out |
| Wednesday, June 19 |
| » Lost to Phillies (35-30), 5-4 | Veteran's Stadium (1-2) | 33-34 | |
| » W: Jim Lonborg (9-5) L: Tom Griffin (7-3) S: Mac Scarce (4) | Fourth | 11 out |
| Friday, June 21 |
| » Defeated Padres (29-43), 2-0 | Astrodome (21-15) | 34-34 | |
| » W: Larry Dierker (5-3) L: Bill Greif (2-10) S: Fred Scherman (4) | Fourth | 11 out |
| Saturday, June 22 |
| » Lost to Padres (30-43), 6-2 | Astrodome (21-16) | 34-35 | |
| » W: Randy Jones (4-11) L: Don Wilson (3-5) S: Dave Tomlin (2) | Fourth | 12 out |
| Sunday, June 23 |
| » Defeated Padres (30-44), 8-2 | Astrodome (22-16) | 35-35 | |
| » W: Claude Osteen (6-7) L: Dave Freisleben (6-3) | Fourth | 12 out |
| Monday, June 24 |
| » Defeated Reds (39-29), 6-1 | Astrodome (23-16) | 36-35 | Won 2 |
| » W: Tom Griffin (8-3) L: Don Gullett (7-5) | Fourth | 11 out |
| Tuesday, June 25 |
| » Lost to Reds (40-29), 3-2 | Astrodome (23-17) | 36-36 | |
| » W: Jack Billingham (7-6) L: Larry Dierker (5-4) S: Clay Carroll (2) | Fourth | 12 out |
| Wednesday, June 26 |
| » Lost to Reds (41-29), 9-1 | Astrodome (23-18) | 36-37 | Lost 2 |
| » W: Fred Norman (8-5) L: Don Wilson (3-6) | Fourth | 13 out |
| Friday, June 28 |
| » Lost to Padres (34-45), 5-4 | San Diego/Jack Murphy Stadium (3-1) | 36-38 | Lost 3 |
| » W: Vicente Romo (4-3) L: Ken Forsch (3-3) S: Larry Hardy (1) | Fourth | 14 out |
| Saturday, June 29 |
| » Defeated Padres (34-46), 3-0 | San Diego/Jack Murphy Stadium (4-1) | 37-38 | |
| » W: Tom Griffin (9-3) L: Dan Spillner (4-2) | Fourth | 14 out |
| Sunday, June 30 |
| » Defeated Padres (34-47), 3-1 | San Diego/Jack Murphy Stadium (5-1) | 38-38 | Won 2 |
| » W: Mike Cosgrove (3-0) L: Lowell Palmer (1-1) S: Ken Forsch (4) | Fourth | 14½ out |
| » Lost to Padres (35-47), 6-5 | San Diego/Jack Murphy Stadium (5-2) | 38-39 | |
| » W: Dave Tomlin (2-0) L: Jerry Johnson (2-1) | Fourth | 14½ out |
| Monday, July 1 |
| » Defeated Braves (42-36), 3-0 | Atlanta-Fulton County Stadium (2-1) | 39-39 | |
| » W: Don Wilson (4-6) L: Phil Niekro (8-7) | Fourth | 14 out |
| Tuesday, July 2 |
| » Defeated Braves (42-37), 5-1 | Atlanta-Fulton County Stadium (3-1) | 40-39 | Won 2 |
| » W: Claude Osteen (7-7) L: Roric Harrison (6-10) | Fourth | 14 out |
| Wednesday, July 3 |
| » Lost to Braves (43-37), 5-4 | Atlanta-Fulton County Stadium (3-2) | 40-40 | |
| » W: Danny Frisella (3-2) L: Fred Scherman (1-4) | Fourth | 14½ out |
| Thursday, July 4 |
| » Defeated Braves (43-38), 4-3 | Atlanta-Fulton County Stadium (4-2) | 41-40 | |
| » W: Mike Cosgrove (4-0) L: Tom House (1-2) | Fourth | 14½ out |
| Friday, July 5 |
| » Defeated Pirates (35-42), 7-1 | Astrodome (24-18) | 42-40 | Won 2 |
| » W: Larry Dierker (6-4) L: Dock Ellis (3-7) | Fourth | 14 out |
| Saturday, July 6 |
| » Defeated Pirates (35-43), 1-0 | Astrodome (25-18) | 43-40 | Won 3 |
| » W: Don Wilson (5-6) L: Bruce Kison (4-4) | Fourth | 13 out |
| Sunday, July 7 |
| » Lost to Pirates (36-43), 6-4 | Astrodome (25-19) | 43-41 | |
| » W: Dave Giusti (3-3) L: Fred Scherman (1-5) | Fourth | 14½ out |
| Monday, July 8 |
| » Defeated Cardinals (43-39), 4-1 | Astrodome (26-19) | 44-41 | |
| » W: Tom Griffin (10-3) L: Lynn McGlothen (12-4) | Fourth | 14½ out |
| Tuesday, July 9 |
| » Defeated Cardinals (43-40), 5-2 | Astrodome (27-19) | 45-41 | Won 2 |
| » W: Dave Roberts (6-7) L: Jack Curtis (4-10) | Third | 14½ out |
| Wednesday, July 10 |
| » Defeated Cardinals (43-41), 3-2 | Astrodome (28-19) | 46-41 | Won 3 |
| » W: Mike Cosgrove (5-0) L: Orlando Pena (5-1) | Third | 13½ out |
| Friday, July 12 |
| » Defeated Cubs (37-47), 9-4 | Astrodome (29-19) | 47-41 | Won 4 |
| » W: Don Wilson (6-6) L: Rick Reuschel (8-7) | Third | 12½ out |
| Saturday, July 13 |
| » Defeated Cubs (37-48), 4-0 | Astrodome (30-19) | 48-41 | Won 5 |
| » W: Claude Osteen (8-7) L: Ray Burris (3-2) | Third | 12½ out |
| Sunday, July 14 |
| » Defeated Cubs (37-49), 7-6 | Astrodome (31-19) | 49-41 | Won 6 |
| » W: Jim York (1-1) L: Oscar Zamora (1-3) | Third | 11½ out |
| Monday, July 15 |
| » Lost to Pirates (39-49), 3-1 | Three Rivers Stadium (1-3) | 49-42 | |
| » W: Dock Ellis (4-8) L: Dave Roberts (6-8) | Third | 12 out |
| Tuesday, July 16 |
| » Lost to Pirates (40-49), 6-2 | Three Rivers Stadium (1-4) | 49-43 | Lost 2 |
| » W: Jim Rooker (6-7) L: Larry Dierker (6-5) | Third | 12 out |
| Wednesday, July 17 |
| » Lost to Pirates (41-49), 11-3 | Three Rivers Stadium (1-5) | 49-44 | Lost 3 |
| » W: Larry Demery (1-4) L: Don Wilson (6-7) | Third | 12 out |
| Thursday, July 18 |
| » Defeated Cardinals (44-48), 8-2 | Busch Stadium II (2-1) | 50-44 | |
| » W: Claude Osteen (9-7) L: Lynn McGlothen (12-6) | Third | 12 out |
| Friday, July 19 |
| » Defeated Cardinals (44-49), 5-1 | Busch Stadium II (3-1) | 51-44 | Won 2 |
| » W: Tom Griffin (11-3) L: Ray Bare (0-2) | Third | 12 out |
| Saturday, July 20 |
| » Lost to Cardinals (45-49), 6-5 | Busch Stadium II (3-2) | 51-45 | |
| » W: Al Hrabosky (3-1) L: Mike Cosgrove (5-1) | Third | 12 out |
| Sunday, July 21 |
| » Lost to Cardinals (46-49), 9-1 | Busch Stadium II (3-3) | 51-46 | Lost 2 |
| » W: Bob Forsch (2-2) L: Larry Dierker (6-6) | Third | 12 out |
| Thursday, July 25 |
| » Lost to Dodgers (64-34), 11-3 | Astrodome (31-20) | 51-47 | Lost 3 |
| » W: Don Sutton (7-8) L: Claude Osteen (9-8) | Third | 14 out |
| » Lost to Dodgers (65-34), 2-0 | Astrodome (31-21) | 51-48 | Lost 4 |
| » W: Doug Rau (9-6) L: Don Wilson (6-8) | Third | 14 out |
| Friday, July 26 |
| » Defeated Dodgers (65-35), 8-7 | Astrodome (32-21) | 52-48 | |
| » W: Ken Forsch (4-3) L: Mike Marshall (11-5) | Third | 13 out |
| Saturday, July 27 |
| » Defeated Giants (46-56), 11-3 | Astrodome (33-21) | 53-48 | Won 2 |
| » W: Larry Dierker (7-6) L: John D'Acquisto (9-8) | Third | 12 out |
| Sunday, July 28 |
| » Defeated Giants (46-57), 3-2 | Astrodome (34-21) | 54-48 | Won 3 |
| » W: Jim York (2-1) L: Randy Moffitt (4-5) | Third | 11 out |
| Monday, July 29 |
| » Lost to Giants (47-57), 7-2 | Astrodome (34-22) | 54-49 | |
| » W: Ed Halicki (1-3) L: Claude Osteen (9-9) | Third | 12 out |
| Tuesday, July 30 |
| » Defeated Reds (62-43), 8-4 | Riverfront Stadium (2-3) | 55-49 | |
| » W: Don Wilson (7-8) L: Fred Norman (10-10) | Third | 12 out |
| Wednesday, July 31 |
| » Lost to Reds (63-43), 4-0 | Riverfront Stadium (2-4) | 55-50 | |
| » W: Don Gullett (13-7) L: Tom Griffin (11-4) | Third | 13 out |
| Saturday, August 3 |
| » Lost to Dodgers (71-37), 5-1 | Dodger Stadium (0-5) | 55-51 | Lost 2 |
| » W: Andy Messersmith (13-2) L: Larry Dierker (7-7) | Third | 15 out |
| Sunday, August 4 |
| » Lost to Dodgers (72-37), 2-1 | Dodger Stadium (0-6) | 55-52 | Lost 3 |
| » W: Geoff Zahn (2-1) L: Dave Roberts (6-9) S: Mike Marshall (16) | Third | 16 out |
| Monday, August 5 |
| » Defeated Giants (50-62), 7-2 | Candlestick Park (1-3) | 56-52 | |
| » W: Don Wilson (8-8) L: Charlie Williams (1-3) | Third | 16 out |
| Tuesday, August 6 |
| » Defeated Giants (50-63), 13-4 | Candlestick Park (2-3) | 57-52 | Won 2 |
| » W: Mike Cosgrove (6-1) L: Ed Halicki (1-5) | Third | 15 out |
| Wednesday, August 7 |
| » Defeated Braves (57-54), 6-4 | Astrodome (35-22) | 58-52 | Won 3 |
| » W: Fred Scherman (2-5) L: Max Leon (2-4) S: Ken Forsch (5) | Third | 14 out |
| Thursday, August 8 |
| » Lost to Braves (58-54), 1-0 | Astrodome (35-23) | 58-53 | |
| » W: Ron Reed (7-6) L: Dave Roberts (6-10) | Third | 14½ out |
| Friday, August 9 |
| » Lost to Expos (53-58), 4-3 | Astrodome (35-24) | 58-54 | Lost 2 |
| » W: Dennis Blair (7-4) L: Don Wilson (8-9) S: Don Carrithers (1) | Fourth | 14½ out |
| Saturday, August 10 |
| » Lost to Expos (54-58), 2-1 | Astrodome (35-25) | 58-55 | Lost 3 |
| » W: Steve Rogers (12-14) L: Tom Griffin (11-5) | Fourth | 15½ out |
| Sunday, August 11 |
| » Lost to Expos (55-58), 5-2 | Astrodome (35-26) | 58-56 | Lost 4 |
| » W: Steve Renko (9-11) L: Larry Dierker (7-8) S: Chuck Taylor (9) | Fourth | 16½ out |
| Tuesday, August 13 |
| » Defeated Cubs (46-67), 3-1 | Wrigley Field (2-2) | 59-56 | |
| » W: Dave Roberts (7-10) L: Bill Bonham (10-15) | Fourth | 15 out |
| Wednesday, August 14 |
| » Lost to Cubs (47-67), 6-5 | Wrigley Field (2-3) | 59-57 | |
| » W: Steve Stone (4-4) L: Don Wilson (8-10) S: Jim Todd (1) | Fourth | 15 out |
| Thursday, August 15 |
| » Lost to Cubs (48-67), 5-3 | Wrigley Field (2-4) | 59-58 | Lost 2 |
| » W: Jim Todd (3-2) L: Ken Forsch (4-4) | Fourth | 15½ out |
| Friday, August 16 |
| » Defeated Expos (55-61), 8-3 | Parc Jarry (4-0) | 60-58 | |
| » W: Tom Griffin (12-5) L: Steve Rogers (12-15) S: Mike Cosgrove (1) | Fourth | 14½ out |
| Future Astro Roger Cedeno is born in Valencia, Venezuela. |
| Saturday, August 17 |
| » Lost to Expos (56-61), 3-2 | Parc Jarry (4-1) | 60-59 | |
| » W: Chuck Taylor (5-1) L: Ken Forsch (4-5) | Fourth | 14½ out |
| Sunday, August 18 |
| » Defeated Expos (56-62), 3-0 | Parc Jarry (5-1) | 61-59 | |
| » W: Dave Roberts (8-10) L: Tom Walker (2-3) | Fourth | 13½ out |
| Monday, August 19 |
| » Defeated Mets (52-66), 2-1 | Astrodome (36-26) | 62-59 | Won 2 |
| » W: Ken Forsch (5-5) L: Tom Seaver (7-8) | Fourth | 13½ out |
| Tuesday, August 20 |
| » Defeated Mets (52-67), 6-2 | Astrodome (37-26) | 63-59 | Won 3 |
| » W: J.R. Richard (1-0) L: Ray Sadecki (4-7) S: Mike Cosgrove (2) | Fourth | 13½ out |
| Wednesday, August 21 |
| » Lost to Mets (53-67), 10-2 | Astrodome (37-27) | 63-60 | |
| » W: Jerry Koosman (12-8) L: Tom Griffin (12-6) | Fourth | 14½ out |
| Friday, August 23 |
| » Defeated Phillies (63-62), 1-0 | Astrodome (38-27) | 64-60 | |
| » W: Larry Dierker (8-8) L: Dick Ruthven (6-10) | Fourth | 13½ out |
| Saturday, August 24 |
| » Defeated Phillies (63-63), 1-0 | Astrodome (39-27) | 65-60 | Won 2 |
| » W: Dave Roberts (9-10) L: Steve Carlton (14-9) | Fourth | 13½ out |
| Sunday, August 25 |
| » Defeated Phillies (63-64), 5-0 | Astrodome (40-27) | 66-60 | Won 3 |
| » W: Don Wilson (9-10) L: Wayne Twitchell (6-6) | Fourth | 13½ out |
| Monday, August 26 |
| » Lost to Mets (55-70), 5-4 | Shea Stadium (1-2) | 66-61 | |
| » W: Jerry Koosman (13-8) L: Mike Cosgrove (6-2) | Fourth | 14 out |
| Tuesday, August 27 |
| » Lost to Mets (56-70), 4-2 | Shea Stadium (1-3) | 66-62 | Lost 2 |
| » W: Tug McGraw (5-7) L: Tom Griffin (12-7) S: Harry Parker (3) | Fourth | 15 out |
| » Major-league debuts: Benny Ayala (Mets) |
| Wednesday, August 28 |
| » Defeated Mets (56-71), 3-2 | Shea Stadium (2-3) | 67-62 | |
| » W: Ramon de los Santos (1-0) L: Jerry Cram (0-1) S: Jim York (1) | Fourth | 15 out |
| Thursday, August 29 |
| » Lost to Mets (57-71), 7-0 | Shea Stadium (2-4) | 67-63 | |
| » W: Tom Seaver (8-8) L: Dave Roberts (9-11) | Fourth | 16 out |
| Friday, August 30 |
| » Defeated Phillies (64-67), 3-2 | Veteran's Stadium (2-2) | 68-63 | |
| » W: Don Wilson (10-10) L: Wayne Twitchell (6-7) S: Ken Forsch (6) | Fourth | 15 out |
| Saturday, August 31 |
| » Lost to Phillies (65-67), 10-6 | Veteran's Stadium (2-3) | 68-64 | |
| » W: Larry Christenson (1-0) L: J.R. Richard (1-1) | Fourth | 15 out |
| Sunday, September 1 |
| » Lost to Phillies (66-67), 8-1 | Veteran's Stadium (2-4) | 68-65 | Lost 2 |
| » W: Dick Ruthven (7-11) L: Tom Griffin (12-8) | Fourth | 16 out |
| Monday, September 2 |
| » Defeated Reds (81-54), 4-3 | Astrodome (41-27) | 69-65 | |
| » W: Larry Dierker (9-8) L: Tom Carroll (4-2) S: Ken Forsch (7) | Fourth | 15 out |
| Tuesday, September 3 |
| » Lost to Reds (82-54), 7-5 | Astrodome (41-28) | 69-66 | |
| » W: Pedro Borbon (9-6) L: Ken Forsch (5-6) | Fourth | 15 out |
| Wednesday, September 4 |
| » Lost to Reds (83-54), 2-1 | Astrodome (41-29) | 69-67 | Lost 2 |
| » W: Jack Billingham (18-8) L: Don Wilson (10-11) | Fourth | 16 out |
| Friday, September 6 |
| » Defeated Padres (50-89), 4-3 | Astrodome (42-29) | 70-67 | |
| » W: J.R. Richard (2-1) L: Dan Spillner (6-10) | Fourth | 16 out |
| Saturday, September 7 |
| » Lost to Padres (51-89), 8-4 | Astrodome (42-30) | 70-68 | |
| » W: Bill Greif (7-17) L: Mike Cosgrove (6-3) S: Rusty Gerhardt (1) | Fourth | 16 out |
| » Major-league debuts: Paul Siebert (Astros) |
| Sunday, September 8 |
| » Defeated Padres (51-90), 3-2 | Astrodome (43-30) | 71-68 | |
| » W: Tom Griffin (13-8) L: Randy Jones (7-20) S: Ken Forsch (8) | Fourth | 16 out |
| Monday, September 9 |
| » Lost to Giants (65-76), 8-6 | Astrodome (43-31) | 71-69 | |
| » W: John Montefusco (2-0) L: Larry Dierker (9-9) S: Elias Sosa (6) | Fourth | 17 out |
| Tuesday, September 10 |
| » Lost to Giants (66-76), 6-5 | Astrodome (43-32) | 71-70 | Lost 2 |
| » W: John Morris (1-0) L: Ken Forsch (5-7) S: Randy Moffitt (15) | Fourth | 18 out |
| » Major-league debuts: Gary Lavelle (Giants) |
| Wednesday, September 11 |
| » Lost to Padres (52-92), 2-0 | San Diego/Jack Murphy Stadium (5-3) | 71-71 | Lost 3 |
| » W: Dan Spillner (7-10) L: Don Wilson (10-12) | Fourth | 19 out |
| Thursday, September 12 |
| » Lost to Padres (53-92), 4-1 | San Diego/Jack Murphy Stadium (5-4) | 71-72 | Lost 4 |
| » W: Bill Greif (8-17) L: Tom Griffin (13-9) | Fourth | 20 out |
| Friday, September 13 |
| » Defeated Giants (66-79), 5-4 | Candlestick Park (3-3) | 72-72 | |
| » W: Mike Cosgrove (7-3) L: Ron Bryant (3-15) S: Ken Forsch (9) | Fourth | 19 out |
| Saturday, September 14 |
| » Defeated Giants (66-80), 5-0 | Candlestick Park (4-3) | 73-72 | Won 2 |
| » W: Larry Dierker (10-9) L: John Montefusco (2-1) | Fourth | 18 out |
| Sunday, September 15 |
| » Defeated Giants (66-81), 6-0 | Candlestick Park (5-3) | 74-72 | Won 3 |
| » W: Paul Siebert (1-0) L: Mike Caldwell (13-4) | Fourth | 18½ out |
| » Lost to Giants (67-81), 8-4 | Candlestick Park (5-4) | 74-73 | |
| » W: John D'Acquisto (12-12) L: Dave Roberts (9-12) | Fourth | 18½ out |
| Monday, September 16 |
| » Lost to Dodgers (93-54), 7-2 | Dodger Stadium (0-7) | 74-74 | Lost 2 |
| » W: Andy Messersmith (18-6) L: Don Wilson (10-13) | Fourth | 19½ out |
| Tuesday, September 17 |
| » Defeated Dodgers (93-55), 7-0 | Dodger Stadium (1-7) | 75-74 | |
| » W: Tom Griffin (14-9) L: Doug Rau (13-9) | Fourth | 18½ out |
| Wednesday, September 18 |
| » Defeated Dodgers (93-56), 3-2 | Dodger Stadium (2-7) | 76-74 | Won 2 |
| » W: Ken Forsch (6-7) L: Charlie Hough (8-4) | Fourth | 17½ out |
| Friday, September 20 |
| » Lost to Braves (84-68), 1-0 | Astrodome (43-33) | 76-75 | |
| » W: Phil Niekro (18-12) L: J.R. Richard (2-2) | Fourth | 19 out |
| Saturday, September 21 |
| » Defeated Braves (84-69), 6-5 | Astrodome (44-33) | 77-75 | |
| » W: Ken Forsch (7-7) L: Max Leon (4-6) | Fourth | 18 out |
| Future Astro Manuel Barrios is born in Cabecera, Panama. |
| Sunday, September 22 |
| » Defeated Braves (84-70), 3-2 | Astrodome (45-33) | 78-75 | Won 2 |
| » W: Ken Forsch (8-7) L: Max Leon (4-7) | Fourth | 18 out |
| Tuesday, September 24 |
| » Lost to Reds (93-62), 5-1 | Riverfront Stadium (2-5) | 78-76 | |
| » W: Fred Norman (13-12) L: Tom Griffin (14-10) | Fourth | 19½ out |
| Wednesday, September 25 |
| » Lost to Reds (94-62), 4-1 | Riverfront Stadium (2-6) | 78-77 | Lost 2 |
| » W: Clay Kirby (11-9) L: Larry Dierker (10-10) S: Rawly Eastwick (1) | Fourth | 19½ out |
| Thursday, September 26 |
| » Lost to Reds (95-62), 10-6 | Riverfront Stadium (2-7) | 78-78 | Lost 3 |
| » W: Tom Hall (2-1) L: Jim York (2-2) S: Rawly Eastwick (2) | Fourth | 20½ out |
| Saturday, September 28 |
| » Defeated Braves (85-73), 5-0 | Atlanta-Fulton County Stadium (5-2) | 79-78 | |
| » W: Don Wilson (11-13) L: Ron Reed (10-11) | Fourth | 20½ out |
| » Lost to Braves (86-73), 6-2 | Atlanta-Fulton County Stadium (5-3) | 79-79 | |
| » W: Phil Niekro (19-13) L: Paul Siebert (1-1) | Fourth | 20½ out |
| Sunday, September 29 |
| » Defeated Braves (86-74), 9-6 | Atlanta-Fulton County Stadium (6-3) | 80-79 | |
| » W: Dave Roberts (10-12) L: Carl Morton (16-12) | Fourth | 20 out |
| Monday, September 30 |
| » Defeated Dodgers (100-60), 4-1 | Astrodome (46-33) | 81-79 | Won 2 |
| » W: Larry Dierker (11-10) L: Doug Rau (13-11) S: Ken Forsch (10) | Fourth | 19 out |
| Tuesday, October 1 |
| » Lost to Dodgers (101-60), 8-5 | Astrodome (46-34) | 81-80 | |
| » W: Don Sutton (19-9) L: J.R. Richard (2-3) | Fourth | 20 out |
| Wednesday, October 2 |
| » Lost to Dodgers (102-60), 5-4 | Astrodome (46-35) | 81-81 | Lost 2 |
| » W: Charlie Hough (9-4) L: Ramon de los Santos (1-1) S: Eddie Solomon (1) | Fourth | 21 out |
| Tuesday, October 15 |
| Future Astro Mendy Lopez is born in Santo Domingo, D.R. |
| Sunday, November 17 |
| Future Astro Jim Mann is born in Brockton, MA. |
| Friday, December 27 |
| Future Astro Nate Bland is born in Birmingham, AL. |
Game information provided by Retrosheet (www.retrosheet.org) |