| Sunday, January 5 |
| Former Astro Don Wilson dies in Houston, TX at the age of 30. |
| Friday, February 28 |
| Future Astro Ricky Stone is born in Hamilton, OH. |
| Monday, April 7 |
| » Defeated Braves (0-1), 6-2 | Astrodome (1-0) | 1-0 | |
| » W: Larry Dierker (1-0) L: Phil Niekro (0-1) | First | -- |
| » Major-league debuts: Rob Andrews (Astros) |
| Tuesday, April 8 |
| » Lost to Braves (1-1), 2-0 | Astrodome (1-1) | 1-1 | |
| » W: Carl Morton (1-0) L: Doug Konieczny (0-1) | Third | ½ out |
| Wednesday, April 9 |
| » Defeated Braves (1-2), 14-2 | Astrodome (2-1) | 2-1 | |
| » W: Dave Roberts (1-0) L: Ron Reed (0-1) | Second | ½ out |
| » Major-league debuts: Pablo Torrealba (Braves) |
| Friday, April 11 |
| » Lost to Dodgers (1-3), 7-0 | Astrodome (2-2) | 2-2 | |
| » W: Don Sutton (1-0) L: Tom Griffin (0-1) | Third | 1 out |
| Saturday, April 12 |
| » Defeated Dodgers (1-4), 7-5 | Astrodome (3-2) | 3-2 | |
| » W: Larry Dierker (2-0) L: Juan Marichal (0-1) S: Wayne Granger (1) | Second | 1 out |
| Sunday, April 13 |
| » Lost to Dodgers (2-4), 7-4 | Astrodome (3-3) | 3-3 | |
| » W: Andy Messersmith (1-0) L: Doug Konieczny (0-2) | Fourth | 1 out |
| Tuesday, April 15 |
| » Lost to Braves (4-4), 6-1 | Atlanta-Fulton County Stadium (0-1) | 3-4 | Lost 2 |
| » W: Phil Niekro (1-1) L: J.R. Richard (0-1) | Third | 1½ out |
| Wednesday, April 16 |
| » Lost to Braves (5-4), 5-2 | Atlanta-Fulton County Stadium (0-2) | 3-5 | Lost 3 |
| » W: Buzz Capra (2-0) L: Larry Dierker (2-1) | Fifth | 1½ out |
| Thursday, April 17 |
| » Lost to Braves (6-4), 2-1 | Atlanta-Fulton County Stadium (0-3) | 3-6 | Lost 4 |
| » W: Carl Morton (3-0) L: Dave Roberts (1-1) | Fifth | 2½ out |
| Friday, April 18 |
| » Lost to Reds (5-6), 5-2 | Riverfront Stadium (0-1) | 3-7 | Lost 5 |
| » W: Don Gullett (2-0) L: Tom Griffin (0-2) | Fifth | 3 out |
| Saturday, April 19 |
| » Lost to Reds (6-6), 9-8 | Riverfront Stadium (0-2) | 3-8 | Lost 6 |
| » W: Clay Carroll (2-2) L: Ken Forsch (0-1) | Fifth | 4 out |
| Sunday, April 20 |
| » Lost to Reds (7-6), 5-3 | Riverfront Stadium (0-3) | 3-9 | Lost 7 |
| » W: Clay Carroll (3-2) L: Fred Scherman (0-1) | Fifth | 3½ out |
| » Defeated Reds (7-7), 7-6 | Riverfront Stadium (1-3) | 4-9 | |
| » W: J.R. Richard (1-1) L: Clay Kirby (0-2) S: Wayne Granger (2) | Fifth | 3½ out |
| Monday, April 21 |
| » Lost to Padres (7-4), 4-0 | Astrodome (3-4) | 4-10 | |
| » W: Randy Jones (2-0) L: Jim Crawford (0-1) | Sixth | 4½ out |
| Tuesday, April 22 |
| » Lost to Padres (8-4), 2-1 | Astrodome (3-5) | 4-11 | Lost 2 |
| » W: Dan Spillner (2-1) L: Tom Griffin (0-3) | Fifth | 5½ out |
| Wednesday, April 23 |
| » Defeated Giants (7-7), 3-2 | Astrodome (4-5) | 5-11 | |
| » W: Doug Konieczny (1-2) L: John Montefusco (2-1) S: Ken Forsch (1) | Sixth | 6 out |
| » Lost to Giants (8-7), 3-0 | Astrodome (4-6) | 5-12 | |
| » W: Pete Falcone (2-1) L: Dave Roberts (1-2) | Sixth | 6 out |
| Thursday, April 24 |
| » Lost to Giants (9-7), 6-5 | Astrodome (4-7) | 5-13 | Lost 2 |
| » W: Gary Lavelle (2-0) L: Ken Forsch (0-2) S: Dave Heaverlo (1) | Fifth | 6 out |
| Friday, April 25 |
| » Defeated Reds (9-10), 6-4 | Astrodome (5-7) | 6-13 | |
| » W: Larry Dierker (3-1) L: Pat Darcy (1-1) S: Ken Forsch (2) | Sixth | 6 out |
| Saturday, April 26 |
| » Lost to Reds (10-10), 9-3 | Astrodome (5-8) | 6-14 | |
| » W: Fred Norman (1-1) L: Tom Griffin (0-4) | Sixth | 6 out |
| Sunday, April 27 |
| » Lost to Reds (11-10), 6-2 | Astrodome (5-9) | 6-15 | Lost 2 |
| » W: Pedro Borbon (2-1) L: Doug Konieczny (1-3) | Sixth | 6½ out |
| Monday, April 28 |
| » Defeated Padres (10-9), 4-1 | San Diego/Jack Murphy Stadium (1-0) | 7-15 | |
| » W: Dave Roberts (2-2) L: Joe McIntosh (3-1) | Sixth | 6½ out |
| Tuesday, April 29 |
| » Defeated Padres (10-10), 8-2 | San Diego/Jack Murphy Stadium (2-0) | 8-15 | Won 2 |
| » W: J.R. Richard (2-1) L: Dave Freisleben (1-3) | Fifth | 6½ out |
| Wednesday, April 30 |
| » Lost to Padres (11-10), 4-2 | San Diego/Jack Murphy Stadium (2-1) | 8-16 | |
| » W: Sonny Siebert (3-0) L: Larry Dierker (3-2) S: Bill Greif (4) | Sixth | 7½ out |
| Thursday, May 1 |
| » Defeated Padres (11-11), 6-3 | San Diego/Jack Murphy Stadium (3-1) | 9-16 | |
| » W: Ken Forsch (1-2) L: Randy Jones (2-2) S: Jim Crawford (1) | Sixth | 7 out |
| Friday, May 2 |
| » Lost to Giants (11-11), 5-4 | Candlestick Park (0-1) | 9-17 | |
| » W: Randy Moffitt (3-0) L: Jim York (0-1) | Sixth | 8 out |
| Sunday, May 4 |
| » Lost to Giants (12-11), 8-6 | Candlestick Park (0-2) | 9-18 | Lost 2 |
| » W: Jim Barr (2-2) L: Jim York (0-2) | Sixth | 7 out |
| » Defeated Giants (12-12), 12-8 | Candlestick Park (1-2) | 10-18 | |
| » W: J.R. Richard (3-1) L: John D'Acquisto (1-3) S: Wayne Granger (3) | Sixth | 7 out |
| » Major-league debuts: Glenn Adams (Giants) |
| Monday, May 5 |
| » Lost to Dodgers (17-10), 2-0 | Dodger Stadium (0-1) | 10-19 | |
| » W: Doug Rau (4-1) L: Larry Dierker (3-3) | Sixth | 8 out |
| Tuesday, May 6 |
| » Lost to Dodgers (18-10), 3-1 | Dodger Stadium (0-2) | 10-20 | Lost 2 |
| » W: Don Sutton (6-1) L: Doug Konieczny (1-4) | Sixth | 9 out |
| Wednesday, May 7 |
| » Lost to Dodgers (19-10), 5-1 | Dodger Stadium (0-3) | 10-21 | Lost 3 |
| » W: Andy Messersmith (5-0) L: Tom Griffin (0-5) | Sixth | 10 out |
| Friday, May 9 |
| » Lost to Expos (9-13), 5-4 | Parc Jarry (0-1) | 10-22 | Lost 4 |
| » W: Don DeMola (1-0) L: Dave Roberts (2-3) S: Dale Murray (3) | Sixth | 10 out |
| Saturday, May 10 |
| » Lost to Expos (10-13), 8-7 | Parc Jarry (0-2) | 10-23 | Lost 5 |
| » W: Dale Murray (1-2) L: Jim Crawford (0-2) S: John Montague (1) | Sixth | 11 out |
| Sunday, May 11 |
| » Defeated Expos (10-14), 6-0 | Parc Jarry (1-2) | 11-23 | |
| » W: Larry Dierker (4-3) L: Dennis Blair (1-4) | Sixth | 11 out |
| Tuesday, May 13 |
| » Lost to Cubs (19-9), 2-1 | Wrigley Field (0-1) | 11-24 | |
| » W: Steve Stone (5-0) L: Doug Konieczny (1-5) S: Oscar Zamora (4) | Sixth | 12½ out |
| Wednesday, May 14 |
| » Defeated Cubs (19-10), 11-7 | Wrigley Field (1-1) | 12-24 | |
| » W: Tom Griffin (1-5) L: Ray Burris (4-2) S: Joe Niekro (1) | Sixth | 11½ out |
| Thursday, May 15 |
| » Lost to Cubs (20-10), 4-2 | Wrigley Field (1-2) | 12-25 | |
| » W: Rick Reuschel (3-3) L: J.R. Richard (3-2) | Fifth | 12 out |
| Friday, May 16 |
| » Lost to Mets (14-14), 10-2 | Astrodome (5-10) | 12-26 | Lost 2 |
| » W: Tom Seaver (5-3) L: Larry Dierker (4-4) | Fifth | 12 out |
| Saturday, May 17 |
| » Lost to Mets (15-14), 6-4 | Astrodome (5-11) | 12-27 | Lost 3 |
| » W: Jon Matlack (4-3) L: Dave Roberts (2-4) S: Harry Parker (1) | Sixth | 13 out |
| Sunday, May 18 |
| » Defeated Mets (15-15), 12-7 | Astrodome (6-11) | 13-27 | |
| » W: Doug Konieczny (2-5) L: Randy Tate (1-3) S: Jim Crawford (2) | Sixth | 12 out |
| Monday, May 19 |
| » Defeated Phillies (20-15), 4-2 | Astrodome (7-11) | 14-27 | Won 2 |
| » W: Tom Griffin (2-5) L: Steve Carlton (2-5) S: Wayne Granger (4) | Sixth | 12 out |
| Tuesday, May 20 |
| » Defeated Phillies (20-16), 4-2 | Astrodome (8-11) | 15-27 | Won 3 |
| » W: Ken Forsch (2-2) L: Tug McGraw (2-1) S: Joe Niekro (2) | Sixth | 11 out |
| Wednesday, May 21 |
| » Defeated Phillies (20-17), 4-0 | Astrodome (9-11) | 16-27 | Won 4 |
| » W: Larry Dierker (5-4) L: Wayne Twitchell (3-5) | Sixth | 11 out |
| Friday, May 23 |
| » Defeated Expos (13-21), 4-2 | Astrodome (10-11) | 17-27 | Won 5 |
| » W: Dave Roberts (3-4) L: Dennis Blair (2-5) | Sixth | 10½ out |
| Saturday, May 24 |
| » Lost to Expos (14-21), 2-1 | Astrodome (10-12) | 17-28 | |
| » W: Steve Rogers (3-4) L: Doug Konieczny (2-6) | Sixth | 10½ out |
| Sunday, May 25 |
| » Defeated Expos (14-22), 8-7 | Astrodome (11-12) | 18-28 | |
| » W: Joe Niekro (1-0) L: Don DeMola (1-1) | Sixth | 10½ out |
| Monday, May 26 |
| » Lost to Pirates (20-18), 10-2 | Three Rivers Stadium (0-1) | 18-29 | |
| » W: Bruce Kison (4-1) L: J.R. Richard (3-3) | Sixth | 10½ out |
| Tuesday, May 27 |
| » Lost to Pirates (21-18), 6-5 | Three Rivers Stadium (0-2) | 18-30 | Lost 2 |
| » W: Larry Demery (2-0) L: Joe Niekro (1-1) | Sixth | 11½ out |
| Wednesday, May 28 |
| » Lost to Pirates (22-18), 3-0 | Three Rivers Stadium (0-3) | 18-31 | Lost 3 |
| » W: Ken Brett (4-2) L: Dave Roberts (3-5) | Sixth | 11½ out |
| Friday, May 30 |
| » Defeated Phillies (22-22), 5-0 | Veteran's Stadium (1-0) | 19-31 | |
| » W: Doug Konieczny (3-6) L: Jim Lonborg (3-3) | Sixth | 11½ out |
| Saturday, May 31 |
| » Defeated Phillies (22-23), 15-3 | Veteran's Stadium (2-0) | 20-31 | Won 2 |
| » W: J.R. Richard (4-3) L: Wayne Twitchell (3-6) | Sixth | 10½ out |
| Sunday, June 1 |
| » Lost to Phillies (23-23), 5-4 | Veteran's Stadium (2-1) | 20-32 | |
| » W: Tom Underwood (6-3) L: Larry Dierker (5-5) S: Larry Christenson (1) | Sixth | 10½ out |
| Monday, June 2 |
| » Lost to Mets (22-20), 2-0 | Shea Stadium (0-1) | 20-33 | Lost 2 |
| » W: Jon Matlack (7-3) L: Dave Roberts (3-6) | Sixth | 10½ out |
| Tuesday, June 3 |
| » Lost to Mets (23-20), 4-3 | Shea Stadium (0-2) | 20-34 | Lost 3 |
| » W: Tom Hall (1-0) L: Ken Forsch (2-3) S: Bob Apodaca (7) | Sixth | 11½ out |
| Wednesday, June 4 |
| » Lost to Mets (24-20), 1-0 | Shea Stadium (0-3) | 20-35 | Lost 4 |
| » W: Jerry Koosman (5-3) L: Doug Konieczny (3-7) | Sixth | 12½ out |
| Thursday, June 5 |
| » Lost to Mets (25-20), 2-1 | Shea Stadium (0-4) | 20-36 | Lost 5 |
| » W: Tom Seaver (8-4) L: Tom Griffin (2-6) | Sixth | 13 out |
| Future Astro Jason Green is born in Port Hope, ON. |
| Friday, June 6 |
| » Lost to Cardinals (23-25), 6-0 | Astrodome (11-13) | 20-37 | Lost 6 |
| » W: Bob Forsch (6-4) L: Larry Dierker (5-6) | Sixth | 14 out |
| Saturday, June 7 |
| » Lost to Cardinals (24-25), 5-1 | Astrodome (11-14) | 20-38 | Lost 7 |
| » W: Lynn McGlothen (6-4) L: Dave Roberts (3-7) | Sixth | 14 out |
| Sunday, June 8 |
| » Lost to Cardinals (25-25), 5-1 | Astrodome (11-15) | 20-39 | Lost 8 |
| » W: Ron Reed (6-5) L: Ken Forsch (2-4) S: Al Hrabosky (9) | Sixth | 15½ out |
| Monday, June 9 |
| » Lost to Cubs (29-25), 4-3 | Astrodome (11-16) | 20-40 | Lost 9 |
| » W: Oscar Zamora (4-1) L: Wayne Granger (0-1) S: Darold Knowles (7) | Sixth | 15½ out |
| Tuesday, June 10 |
| » Defeated Cubs (29-26), 4-3 | Astrodome (12-16) | 21-40 | |
| » W: Doug Konieczny (4-7) L: Eddie Watt (0-1) | Sixth | 14½ out |
| Wednesday, June 11 |
| » Defeated Pirates (29-23), 5-1 | Astrodome (13-16) | 22-40 | Won 2 |
| » W: Larry Dierker (6-6) L: Bruce Kison (6-2) | Sixth | 14½ out |
| Thursday, June 12 |
| » Lost to Pirates (30-23), 4-2 | Astrodome (13-17) | 22-41 | |
| » W: Dock Ellis (3-3) L: Dave Roberts (3-8) S: Larry Demery (2) | Sixth | 15½ out |
| Friday, June 13 |
| » Lost to Cardinals (27-27), 6-2 | Busch Stadium II (0-1) | 22-42 | Lost 2 |
| » W: Ron Reed (7-5) L: Paul Siebert (0-1) | Sixth | 16½ out |
| Saturday, June 14 |
| » Defeated Cardinals (27-28), 9-0 | Busch Stadium II (1-1) | 23-42 | |
| » W: Tom Griffin (3-6) L: Jack Curtis (4-4) | Sixth | 16½ out |
| Sunday, June 15 |
| » Defeated Cardinals (27-29), 8-7 | Busch Stadium II (2-1) | 24-42 | Won 2 |
| » W: Joe Niekro (2-1) L: Mike Garman (2-3) | Fifth | 15½ out |
| Monday, June 16 |
| » Lost to Dodgers (36-29), 4-2 | Dodger Stadium (0-4) | 24-43 | |
| » W: Don Sutton (11-5) L: Larry Dierker (6-7) | Sixth | 16½ out |
| Tuesday, June 17 |
| » Lost to Dodgers (37-29), 6-1 | Dodger Stadium (0-5) | 24-44 | Lost 2 |
| » W: Andy Messersmith (10-3) L: Dave Roberts (3-9) | Fifth | 16½ out |
| Wednesday, June 18 |
| » Lost to Dodgers (38-29), 4-0 | Dodger Stadium (0-6) | 24-45 | Lost 3 |
| » W: Burt Hooton (6-5) L: Tom Griffin (3-7) | Sixth | 17½ out |
| Friday, June 20 |
| » Lost to Reds (41-26), 7-3 | Astrodome (13-18) | 24-46 | Lost 4 |
| » W: Tom Carroll (1-0) L: Doug Konieczny (4-8) | Sixth | 18½ out |
| Saturday, June 21 |
| » Lost to Reds (42-26), 7-6 | Astrodome (13-19) | 24-47 | Lost 5 |
| » W: Fred Norman (3-3) L: Joe Niekro (2-2) | Sixth | 19½ out |
| Sunday, June 22 |
| » Defeated Reds (42-27), 8-4 | Astrodome (14-19) | 25-47 | |
| » W: Larry Dierker (7-7) L: Gary Nolan (7-5) | Sixth | 18½ out |
| Monday, June 23 |
| » Defeated Dodgers (41-31), 6-5 | Astrodome (15-19) | 26-47 | Won 2 |
| » W: Dave Roberts (4-9) L: Burt Hooton (6-6) S: Wayne Granger (5) | Sixth | 18½ out |
| Tuesday, June 24 |
| » Lost to Dodgers (42-31), 8-3 | Astrodome (15-20) | 26-48 | |
| » W: Doug Rau (7-6) L: Tom Griffin (3-8) | Sixth | 19½ out |
| Wednesday, June 25 |
| » Defeated Dodgers (42-32), 5-4 | Astrodome (16-20) | 27-48 | |
| » W: Wayne Granger (1-1) L: Don Sutton (11-7) | Sixth | 19½ out |
| Thursday, June 26 |
| » Defeated Braves (31-43), 8-4 | Astrodome (17-20) | 28-48 | Won 2 |
| » W: J.R. Richard (5-3) L: Mike Thompson (0-2) | Sixth | 19 out |
| Friday, June 27 |
| » Lost to Braves (32-43), 7-4 | Astrodome (17-21) | 28-49 | |
| » W: Jamie Easterly (1-1) L: Larry Dierker (7-8) S: Max Leon (3) | Sixth | 20 out |
| Future Astro Daryle Ward is born in Lynwood, CA. |
| Saturday, June 28 |
| » Lost to Braves (33-43), 6-3 | Astrodome (17-22) | 28-50 | Lost 2 |
| » W: Mike Beard (2-0) L: Dave Roberts (4-10) S: Tom House (7) | Sixth | 21 out |
| Sunday, June 29 |
| » Lost to Braves (34-43), 3-1 | Astrodome (17-23) | 28-51 | Lost 3 |
| » W: Carl Morton (9-8) L: Ken Forsch (2-5) S: Max Leon (4) | Sixth | 21½ out |
| Monday, June 30 |
| » Lost to Reds (49-28), 9-6 | Riverfront Stadium (1-4) | 28-52 | Lost 4 |
| » W: Clay Kirby (5-3) L: Joe Niekro (2-3) | Sixth | 22½ out |
| Tuesday, July 1 |
| » Lost to Reds (50-28), 8-7 | Riverfront Stadium (1-5) | 28-53 | Lost 5 |
| » W: Pat Darcy (3-5) L: Joe Niekro (2-4) | Sixth | 23½ out |
| Wednesday, July 2 |
| » Lost to Reds (51-28), 4-3 | Riverfront Stadium (1-6) | 28-54 | Lost 6 |
| » W: Rawly Eastwick (1-1) L: Larry Dierker (7-9) | Sixth | 24½ out |
| Future Astro Richard Hidalgo is born in Caracas, Venezuela. |
| Friday, July 4 |
| » Lost to Braves (36-44), 5-4 | Atlanta-Fulton County Stadium (0-4) | 28-55 | Lost 7 |
| » W: Carl Morton (10-8) L: Wayne Granger (1-2) | Sixth | 25 out |
| Saturday, July 5 |
| » Lost to Braves (37-44), 4-3 | Atlanta-Fulton County Stadium (0-5) | 28-56 | Lost 8 |
| » W: Ray Sadecki (2-1) L: Ken Forsch (2-6) S: Elias Sosa (1) | Sixth | 26½ out |
| » Lost to Braves (38-44), 8-4 | Atlanta-Fulton County Stadium (0-6) | 28-57 | Lost 9 |
| » W: Max Leon (1-0) L: Doug Konieczny (4-9) S: Tom House (8) | Sixth | 26½ out |
| Sunday, July 6 |
| » Defeated Braves (38-45), 6-2 | Atlanta-Fulton County Stadium (1-6) | 29-57 | |
| » W: J.R. Richard (6-3) L: Phil Niekro (9-7) S: Jim Crawford (3) | Sixth | 26½ out |
| Monday, July 7 |
| » Defeated Expos (34-44), 5-1 | Astrodome (18-23) | 30-57 | Won 2 |
| » W: Larry Dierker (8-9) L: Steve Rogers (5-7) | Sixth | 26½ out |
| Tuesday, July 8 |
| » Defeated Expos (34-45), 5-1 | Astrodome (19-23) | 31-57 | Won 3 |
| » W: Dave Roberts (5-10) L: Steve Renko (4-7) | Sixth | 26½ out |
| Wednesday, July 9 |
| » Defeated Expos (34-46), 4-3 | Astrodome (20-23) | 32-57 | Won 4 |
| » W: Wayne Granger (2-2) L: Don DeMola (3-3) | Fifth | 26½ out |
| » Major-league debuts: Mike Stanton (Astros) |
| Friday, July 11 |
| » Lost to Phillies (48-39), 2-1 | Astrodome (20-24) | 32-58 | |
| » W: Larry Christenson (4-1) L: Doug Konieczny (4-10) | Sixth | 28 out |
| Saturday, July 12 |
| » Lost to Phillies (49-39), 14-2 | Astrodome (20-25) | 32-59 | Lost 2 |
| » W: Steve Carlton (8-7) L: J.R. Richard (6-4) | Sixth | 29 out |
| Sunday, July 13 |
| » Defeated Phillies (49-40), 9-5 | Astrodome (21-25) | 33-59 | |
| » W: Ken Forsch (3-6) L: Tom Underwood (9-7) S: Dave Roberts (1) | Sixth | 29 out |
| Thursday, July 17 |
| » Lost to Phillies (50-40), 6-5 | Veteran's Stadium (2-2) | 33-60 | |
| » W: Tug McGraw (6-4) L: Ken Forsch (3-7) | Sixth | 29 out |
| Friday, July 18 |
| » Lost to Phillies (51-40), 7-4 | Veteran's Stadium (2-3) | 33-61 | Lost 2 |
| » W: Tom Hilgendorf (2-0) L: J.R. Richard (6-5) S: Gene Garber (6) | Sixth | 30 out |
| Saturday, July 19 |
| » Lost to Phillies (52-40), 1-0 | Veteran's Stadium (2-4) | 33-62 | Lost 3 |
| » W: Larry Christenson (5-1) L: Larry Dierker (8-10) | Sixth | 30 out |
| Sunday, July 20 |
| » Lost to Mets (46-43), 10-9 | Shea Stadium (0-5) | 33-63 | Lost 4 |
| » W: Tom Hall (2-2) L: Wayne Granger (2-3) S: Harry Parker (2) | Sixth | 30 out |
| Monday, July 21 |
| » Defeated Mets (46-44), 6-2 | Shea Stadium (1-5) | 34-63 | |
| » W: Ken Forsch (4-7) L: George Stone (2-2) | Sixth | 30 out |
| Tuesday, July 22 |
| » Lost to Expos (39-51), 2-1 | Parc Jarry (1-3) | 34-64 | |
| » W: Dale Murray (4-3) L: Jose Sosa (0-1) | Sixth | 30 out |
| » Major-league debuts: Jose Sosa (Astros) |
| Wednesday, July 23 |
| » Defeated Expos (39-52), 2-1 | Parc Jarry (2-3) | 35-64 | |
| » W: J.R. Richard (7-5) L: Dennis Blair (6-11) | Sixth | 29 out |
| Thursday, July 24 |
| » Defeated Expos (39-53), 6-5 | Parc Jarry (3-3) | 36-64 | Won 2 |
| » W: Larry Dierker (9-10) L: Steve Renko (4-8) S: Mike Cosgrove (1) | Fifth | 29 out |
| Friday, July 25 |
| » Lost to Giants (48-50), 8-1 | Astrodome (21-26) | 36-65 | |
| » W: Jim Barr (8-8) L: Dave Roberts (5-11) | Sixth | 29½ out |
| Saturday, July 26 |
| » Lost to Giants (49-50), 3-2 | Astrodome (21-27) | 36-66 | Lost 2 |
| » W: Randy Moffitt (4-3) L: Ken Forsch (4-8) S: Gary Lavelle (5) | Sixth | 31 out |
| » Lost to Giants (50-50), 9-3 | Astrodome (21-28) | 36-67 | Lost 3 |
| » W: Tom Bradley (2-2) L: Doug Konieczny (4-11) S: Charlie Williams (2) | Sixth | 31 out |
| Sunday, July 27 |
| » Lost to Giants (51-50), 3-1 | Astrodome (21-29) | 36-68 | Lost 4 |
| » W: John Montefusco (10-4) L: J.R. Richard (7-6) S: Gary Lavelle (6) | Sixth | 31 out |
| Monday, July 28 |
| » Lost to Padres (49-54), 2-0 | Astrodome (21-30) | 36-69 | Lost 5 |
| » W: Dave Freisleben (5-10) L: Larry Dierker (9-11) | Sixth | 32 out |
| Tuesday, July 29 |
| » Defeated Padres (49-55), 6-2 | Astrodome (22-30) | 37-69 | |
| » W: Dave Roberts (6-11) L: Dan Spillner (4-8) | Sixth | 31 out |
| Wednesday, July 30 |
| » Defeated Padres (49-56), 8-4 | Astrodome (23-30) | 38-69 | Won 2 |
| » W: Doug Konieczny (5-11) L: Joe McIntosh (8-9) S: Jose Sosa (1) | Sixth | 31 out |
| Thursday, July 31 |
| » Lost to Padres (50-56), 5-3 | Astrodome (23-31) | 38-70 | |
| » W: Dave Tomlin (2-1) L: Wayne Granger (2-4) S: Bill Greif (8) | Sixth | 32 out |
| Friday, August 1 |
| » Lost to Giants (53-53), 3-2 | Candlestick Park (1-3) | 38-71 | Lost 2 |
| » W: Ed Halicki (5-8) L: J.R. Richard (7-7) | Sixth | 32 out |
| Saturday, August 2 |
| » Lost to Giants (54-53), 8-7 | Candlestick Park (1-4) | 38-72 | Lost 3 |
| » W: Dave Heaverlo (2-0) L: Jim Crawford (0-3) | Sixth | 33 out |
| Sunday, August 3 |
| » Lost to Giants (55-53), 5-4 | Candlestick Park (1-5) | 38-73 | Lost 4 |
| » W: Pete Falcone (8-7) L: Dave Roberts (6-12) S: Randy Moffitt (9) | Sixth | 33½ out |
| » Defeated Giants (55-54), 10-9 | Candlestick Park (2-5) | 39-73 | |
| » W: Jim Crawford (1-3) L: Mike Caldwell (5-11) S: Mike Cosgrove (2) | Sixth | 33½ out |
| » Major-league debuts: Jesus de la Rosa (Astros) |
| Monday, August 4 |
| » Defeated Padres (51-59), 5-3 | San Diego/Jack Murphy Stadium (4-1) | 40-73 | Won 2 |
| » W: Joe Niekro (3-4) L: Dave Freisleben (5-11) S: Mike Cosgrove (3) | Sixth | 33½ out |
| Tuesday, August 5 |
| » Lost to Padres (52-59), 6-5 | San Diego/Jack Murphy Stadium (4-2) | 40-74 | |
| » W: Bill Greif (3-3) L: Wayne Granger (2-5) | Sixth | 34½ out |
| Wednesday, August 6 |
| » Lost to Padres (53-59), 6-1 | San Diego/Jack Murphy Stadium (4-3) | 40-75 | Lost 2 |
| » W: Randy Jones (15-6) L: Larry Dierker (9-12) | Sixth | 35½ out |
| Thursday, August 7 |
| » Defeated Pirates (66-46), 6-1 | Astrodome (24-31) | 41-75 | |
| » W: Dave Roberts (7-12) L: Bruce Kison (9-8) | Sixth | 35 out |
| Friday, August 8 |
| » Defeated Pirates (66-47), 5-3 | Astrodome (25-31) | 42-75 | Won 2 |
| » W: Jim Crawford (2-3) L: Kent Tekulve (0-1) | Sixth | 34 out |
| Saturday, August 9 |
| » Defeated Pirates (66-48), 5-0 | Astrodome (26-31) | 43-75 | Won 3 |
| » W: Joe Niekro (4-4) L: Jerry Reuss (12-8) | Sixth | 34 out |
| Sunday, August 10 |
| » Defeated Pirates (66-49), 5-3 | Astrodome (27-31) | 44-75 | Won 4 |
| » W: J.R. Richard (8-7) L: Jim Rooker (8-8) S: Mike Cosgrove (4) | Sixth | 34 out |
| Monday, August 11 |
| » Defeated Cardinals (60-55), 7-2 | Astrodome (28-31) | 45-75 | Won 5 |
| » W: Larry Dierker (10-12) L: Jack Curtis (8-9) | Sixth | 34 out |
| Tuesday, August 12 |
| » Lost to Cardinals (61-55), 5-4 | Astrodome (28-32) | 45-76 | |
| » W: John Denny (7-3) L: Dave Roberts (7-13) S: Al Hrabosky (17) | Sixth | 35 out |
| Wednesday, August 13 |
| » Lost to Cardinals (62-55), 4-3 | Astrodome (28-33) | 45-77 | Lost 2 |
| » W: Mike Garman (3-4) L: Mike Cosgrove (0-1) S: Bob Gibson (2) | Sixth | 35½ out |
| Thursday, August 14 |
| » Lost to Cubs (56-65), 5-3 | Astrodome (28-34) | 45-78 | Lost 3 |
| » W: Steve Stone (11-5) L: J.R. Richard (8-8) | Sixth | 36½ out |
| Friday, August 15 |
| » Defeated Cubs (56-66), 4-1 | Astrodome (29-34) | 46-78 | |
| » W: Larry Dierker (11-12) L: Bill Bonham (11-9) | Sixth | 36½ out |
| Saturday, August 16 |
| » Lost to Cubs (57-66), 3-2 | Astrodome (29-35) | 46-79 | |
| » W: Rick Reuschel (9-13) L: Dave Roberts (7-14) | Sixth | 37½ out |
| Sunday, August 17 |
| » Lost to Cubs (58-66), 11-7 | Astrodome (29-36) | 46-80 | Lost 2 |
| » W: Ray Burris (10-9) L: Jim Crawford (2-4) | Sixth | 38½ out |
| Monday, August 18 |
| » Defeated Mets (63-59), 4-0 | Astrodome (30-36) | 47-80 | |
| » W: J.R. Richard (9-8) L: Randy Tate (4-12) | Sixth | 38½ out |
| » Major-league debuts: Mike Vail (Mets) |
| Tuesday, August 19 |
| » Lost to Mets (64-59), 6-3 | Astrodome (30-37) | 47-81 | |
| » Manager: Bill Virdon |
| » W: Jon Matlack (14-8) L: Larry Dierker (11-13) S: Jerry Koosman (2) | Sixth | 38½ out |
| Wednesday, August 20 |
| » Defeated Mets (64-60), 5-4 | Astrodome (31-37) | 48-81 | |
| » W: Jim Crawford (3-4) L: Rick Baldwin (2-4) | Sixth | 37½ out |
| Friday, August 22 |
| » Lost to Cubs (60-68), 6-5 | Wrigley Field (1-3) | 48-82 | |
| » W: Darold Knowles (5-6) L: Jim Crawford (3-5) | Sixth | 37 out |
| Saturday, August 23 |
| » Defeated Cubs (60-69), 14-12 | Wrigley Field (2-3) | 49-82 | |
| » W: Jim York (1-2) L: Bill Bonham (11-11) S: Mike Cosgrove (5) | Sixth | 37 out |
| Sunday, August 24 |
| » Defeated Cubs (60-70), 8-4 | Wrigley Field (3-3) | 50-82 | Won 2 |
| » W: Larry Dierker (12-13) L: Ray Burris (10-10) | Sixth | 36 out |
| Monday, August 25 |
| » Tied Cardinals, 3-3 | Busch Stadium II (2-1) | 50-82 | |
| » Starters: Dave Roberts vs Lynn McGlothen | Sixth | 36½ out |
| Tuesday, August 26 |
| » Lost to Cardinals (70-59), 10-9 | Busch Stadium II (2-2) | 50-83 | |
| » W: Al Hrabosky (11-3) L: Jose Sosa (0-2) | Sixth | 38 out |
| » Lost to Cardinals (71-59), 2-1 | Busch Stadium II (2-3) | 50-84 | Lost 2 |
| » W: Eric Rasmussen (3-2) L: Doug Konieczny (5-12) | Sixth | 38 out |
| Future Astro Morgan Ensberg is born in Redondo Beach, CA. |
| Wednesday, August 27 |
| » Defeated Cardinals (71-60), 5-1 | Busch Stadium II (3-3) | 51-84 | |
| » W: Jim York (2-2) L: John Denny (9-4) | Sixth | 38 out |
| Saturday, August 30 |
| » Defeated Pirates (74-58), 7-4 | Three Rivers Stadium (1-3) | 52-84 | Won 2 |
| » W: Larry Dierker (13-13) L: Jerry Reuss (14-10) | Sixth | 39 out |
| Sunday, August 31 |
| » Lost to Pirates (75-58), 9-6 | Three Rivers Stadium (1-4) | 52-85 | |
| » W: Bruce Kison (10-11) L: Jose Sosa (0-3) S: Dave Giusti (15) | Sixth | 39 out |
| Monday, September 1 |
| » Defeated Braves (59-78), 5-3 | Astrodome (32-37) | 53-85 | |
| » W: Doug Konieczny (6-12) L: Jamie Easterly (1-8) S: Joe Niekro (3) | Sixth | 38 out |
| Tuesday, September 2 |
| » Lost to Braves (60-78), 4-1 | Astrodome (32-38) | 53-86 | |
| » W: Carl Morton (16-15) L: Jim York (2-3) S: Bruce Dal Canton (1) | Sixth | 39 out |
| Wednesday, September 3 |
| » Lost to Giants (69-69), 9-4 | Astrodome (32-39) | 53-87 | Lost 2 |
| » W: Pete Falcone (11-9) L: J.R. Richard (9-9) | Sixth | 40 out |
| Thursday, September 4 |
| » Lost to Giants (70-69), 2-1 | Astrodome (32-40) | 53-88 | Lost 3 |
| » W: John Montefusco (13-7) L: Larry Dierker (13-14) S: Randy Moffitt (10) | Sixth | 40 out |
| Friday, September 5 |
| » Defeated Padres (63-78), 2-1 | Astrodome (33-40) | 54-88 | |
| » W: J.R. Richard (10-9) L: Randy Jones (18-9) | Sixth | 40 out |
| Saturday, September 6 |
| » Lost to Padres (64-78), 2-1 | Astrodome (33-41) | 54-89 | |
| » W: Brent Strom (7-5) L: Doug Konieczny (6-13) | Sixth | 41 out |
| Sunday, September 7 |
| » Defeated Padres (64-79), 3-2 | Astrodome (34-41) | 55-89 | |
| » W: Jim York (3-3) L: Danny Frisella (1-6) | Sixth | 41 out |
| Monday, September 8 |
| » Defeated Braves (63-81), 9-6 | Atlanta-Fulton County Stadium (2-6) | 56-89 | Won 2 |
| » W: Jose Sosa (1-3) L: Frank LaCorte (0-1) S: Mike Stanton (1) | Sixth | 41 out |
| » Major-league debuts: Frank LaCorte (Braves) |
| Tuesday, September 9 |
| » Lost to Braves (64-81), 4-1 | Atlanta-Fulton County Stadium (2-7) | 56-90 | |
| » W: Adrian Devine (1-0) L: Larry Dierker (13-15) S: Bruce Dal Canton (3) | Sixth | 41 out |
| Wednesday, September 10 |
| » Defeated Giants (70-75), 6-3 | Candlestick Park (3-5) | 57-90 | |
| » W: Mike Cosgrove (1-1) L: Ed Halicki (9-13) | Sixth | 40 out |
| Thursday, September 11 |
| » Defeated Giants (70-76), 4-3 | Candlestick Park (4-5) | 58-90 | Won 2 |
| » W: Joe Niekro (5-4) L: Randy Moffitt (4-5) S: Jim Crawford (4) | Sixth | 39 out |
| Friday, September 12 |
| » Lost to Padres (68-80), 1-0 | San Diego/Jack Murphy Stadium (4-4) | 58-91 | |
| » W: Dave Tomlin (3-2) L: Jim York (3-4) | Sixth | 40 out |
| Saturday, September 13 |
| » Major-league debuts: Preston Hanna (Braves) |
| Sunday, September 14 |
| » Defeated Padres (68-81), 4-2 | San Diego/Jack Murphy Stadium (5-4) | 59-91 | |
| » W: J.R. Richard (11-9) L: Randy Jones (19-10) S: Joe Niekro (4) | Sixth | 39 out |
| Tuesday, September 16 |
| » Defeated Reds (98-53), 5-1 | Riverfront Stadium (2-6) | 60-91 | Won 2 |
| » W: Larry Dierker (14-15) L: Jack Billingham (15-9) | Sixth | 38 out |
| Wednesday, September 17 |
| » Lost to Reds (99-53), 10-1 | Riverfront Stadium (2-7) | 60-92 | |
| » W: Fred Norman (11-4) L: Mike Stanton (0-1) | Sixth | 39 out |
| Friday, September 19 |
| » Defeated Dodgers (84-70), 6-5 | Astrodome (35-41) | 61-92 | |
| » W: Dave Roberts (8-14) L: Dave Sells (0-1) | Sixth | 39½ out |
| Saturday, September 20 |
| » Lost to Dodgers |