| Tuesday, March 20 |
| Future Astro Wilfredo Rodriguez is born in Bolivar, Venezuela. |
| Wednesday, April 4 |
| » Major-league debuts: Mark Clear (Angels) |
| Friday, April 6 |
| » Defeated Braves (0-1), 2-1 | Astrodome (1-0) | 1-0 | |
| » W: J.R. Richard (1-0) L: Phil Niekro (0-1) S: Joaquin Andujar (1) | Second | ½ out |
| Saturday, April 7 |
| » Defeated Braves (0-2), 6-0 | Astrodome (2-0) | 2-0 | Won 2 |
| » W: Ken Forsch (1-0) L: Larry McWilliams (0-1) | Second | ½ out |
| Sunday, April 8 |
| » Defeated Braves (0-3), 2-0 | Astrodome (3-0) | 3-0 | Won 3 |
| » W: Joe Niekro (1-0) L: Rick Matula (0-1) | First | -- |
| » Major-league debuts: Rick Matula (Braves) |
| Monday, April 9 |
| » Lost to Dodgers (4-1), 2-1 | Astrodome (3-1) | 3-1 | |
| » W: Bob Welch (1-0) L: Vern Ruhle (0-1) S: Jerry Reuss (1) | Second | ½ out |
| Tuesday, April 10 |
| » Defeated Dodgers (4-2), 2-1 | Astrodome (4-1) | 4-1 | |
| » W: J.R. Richard (2-0) L: Burt Hooton (0-1) | First | -- |
| Wednesday, April 11 |
| » Defeated Dodgers (4-3), 10-3 | Astrodome (5-1) | 5-1 | Won 2 |
| » W: Ken Forsch (2-0) L: Don Sutton (1-1) | First | -- |
| Friday, April 13 |
| » Lost to Giants (6-2), 8-7 | Candlestick Park (0-1) | 5-2 | |
| » W: Ed Halicki (1-0) L: Joe Niekro (1-1) S: Gary Lavelle (2) | Second | ½ out |
| » Major-league debuts: Gary Wilson (Astros) |
| Saturday, April 14 |
| » Lost to Giants (7-2), 2-1 | Candlestick Park (0-2) | 5-3 | Lost 2 |
| » W: Vida Blue (3-0) L: Vern Ruhle (0-2) | Second | 1½ out |
| Sunday, April 15 |
| » Defeated Giants (7-3), 4-3 | Candlestick Park (1-2) | 6-3 | |
| » W: J.R. Richard (3-0) L: John Montefusco (1-2) S: Joe Sambito (1) | First | -- |
| » Defeated Giants (7-4), 9-1 | Candlestick Park (2-2) | 7-3 | Won 2 |
| » W: Joaquin Andujar (1-0) L: Tom Griffin (1-1) | First | -- |
| Monday, April 16 |
| » Defeated Dodgers (5-7), 4-0 | Dodger Stadium (1-0) | 8-3 | Won 3 |
| » W: Ken Forsch (3-0) L: Don Sutton (1-2) | First | -- |
| Tuesday, April 17 |
| » Lost to Dodgers (6-7), 10-6 | Dodger Stadium (1-1) | 8-4 | |
| » W: Jerry Reuss (1-0) L: Tom Dixon (0-1) | First | -- |
| Wednesday, April 18 |
| » Defeated Dodgers (6-8), 4-0 | Dodger Stadium (2-1) | 9-4 | |
| » W: Vern Ruhle (1-2) L: Doug Rau (0-2) | First | -- |
| Friday, April 20 |
| » Defeated Pirates (4-8), 5-4 | Astrodome (6-1) | 10-4 | Won 2 |
| » W: Joe Sambito (1-0) L: Jim Bibby (1-1) | First | -- |
| Saturday, April 21 |
| » Defeated Pirates (4-9), 5-4 | Astrodome (7-1) | 11-4 | Won 3 |
| » W: Joaquin Andujar (2-0) L: Kent Tekulve (0-3) | First | -- |
| Sunday, April 22 |
| » Defeated Pirates (4-10), 3-2 | Astrodome (8-1) | 12-4 | Won 4 |
| » W: Joaquin Andujar (3-0) L: John Candelaria (0-1) S: Joe Sambito (2) | First | -- |
| Wednesday, April 25 |
| » Lost to Cubs (7-6), 4-0 | Wrigley Field (0-1) | 12-5 | |
| » W: Dennis Lamp (2-0) L: Vern Ruhle (1-3) | First | -- |
| Thursday, April 26 |
| » Defeated Cubs (7-7), 6-2 | Wrigley Field (1-1) | 13-5 | |
| » W: J.R. Richard (4-0) L: Lynn McGlothen (2-2) S: Joe Sambito (3) | First | -- |
| Friday, April 27 |
| » Defeated Pirates (6-11), 9-8 | Three Rivers Stadium (1-0) | 14-5 | Won 2 |
| » W: Frank Riccelli (1-0) L: Ed Whitson (1-1) | First | -- |
| Sunday, April 29 |
| » Lost to Pirates (7-11), 10-5 | Three Rivers Stadium (1-1) | 14-6 | |
| » W: Bruce Kison (1-0) L: Joe Niekro (1-2) S: Grant Jackson (3) | First | -- |
| Monday, April 30 |
| » Defeated Cardinals (9-10), 6-5 | Busch Stadium II (1-0) | 15-6 | |
| » W: Joe Sambito (2-0) L: Tom Bruno (1-1) S: Joaquin Andujar (2) | First | -- |
| Tuesday, May 1 |
| » Lost to Cardinals (10-10), 7-6 | Busch Stadium II (1-1) | 15-7 | |
| » W: Darold Knowles (1-0) L: Joe Sambito (2-1) | First | -- |
| Wednesday, May 2 |
| » Lost to Cardinals (11-10), 5-2 | Busch Stadium II (1-2) | 15-8 | Lost 2 |
| » W: John Denny (2-2) L: Ken Forsch (3-1) | First | -- |
| Thursday, May 3 |
| » Defeated Cardinals (11-11), 4-1 | Busch Stadium II (2-2) | 16-8 | |
| » W: Joe Niekro (2-2) L: Pete Vuckovich (2-1) S: Joaquin Andujar (3) | First | -- |
| Friday, May 4 |
| » Lost to Reds (13-11), 6-5 | Riverfront Stadium (0-1) | 16-9 | |
| » W: Doug Bair (2-0) L: Frank Riccelli (1-1) | First | -- |
| Saturday, May 5 |
| » Lost to Reds (14-11), 6-2 | Riverfront Stadium (0-2) | 16-10 | Lost 2 |
| » W: Tom Hume (3-3) L: Joaquin Andujar (3-1) S: Frank Pastore (3) | First | -- |
| Sunday, May 6 |
| » Lost to Reds (15-11), 17-5 | Riverfront Stadium (0-3) | 16-11 | Lost 3 |
| » W: Pedro Borbon (1-0) L: J.R. Richard (4-1) | First | -- |
| » Defeated Reds (15-12), 8-2 | Riverfront Stadium (1-3) | 17-11 | |
| » W: Frank Riccelli (2-1) L: Fred Norman (1-4) | First | -- |
| Tuesday, May 8 |
| » Lost to Cardinals (14-12), 4-1 | Astrodome (8-2) | 17-12 | |
| » W: Pete Vuckovich (3-2) L: Ken Forsch (3-2) S: Darold Knowles (3) | First | -- |
| Wednesday, May 9 |
| » Defeated Cardinals (14-13), 5-4 | Astrodome (9-2) | 18-12 | |
| » W: Bo McLaughlin (1-0) L: Tom Bruno (1-2) | First | -- |
| Thursday, May 10 |
| » Lost to Cardinals (15-13), 3-1 | Astrodome (9-3) | 18-13 | |
| » W: Bob Sykes (3-2) L: J.R. Richard (4-2) S: Mark Littell (1) | First | -- |
| Friday, May 11 |
| » Lost to Cubs (14-12), 5-3 | Astrodome (9-4) | 18-14 | Lost 2 |
| » W: Rick Reuschel (2-4) L: Frank Riccelli (2-2) S: Bruce Sutter (6) | Second | ½ out |
| Saturday, May 12 |
| » Defeated Cubs (14-13), 11-3 | Astrodome (10-4) | 19-14 | |
| » W: Ken Forsch (4-2) L: Lynn McGlothen (4-4) | Second | 1 out |
| » Lost to Cubs (15-13), 2-0 | Astrodome (10-5) | 19-15 | |
| » W: Ken Holtzman (3-2) L: Rick Williams (0-1) | Second | 1 out |
| » Major-league debuts: Bill Caudill (Cubs) |
| Sunday, May 13 |
| » Defeated Cubs (15-14), 3-0 | Astrodome (11-5) | 20-15 | |
| » W: Joe Niekro (3-2) L: Mike Krukow (1-2) | Second | 1 out |
| Tuesday, May 15 |
| » Lost to Giants (17-18), 8-1 | Astrodome (11-6) | 20-16 | |
| » W: Philip Nastu (1-2) L: J.R. Richard (4-3) | Second | ½ out |
| Wednesday, May 16 |
| » Lost to Giants (18-18), 8-4 | Astrodome (11-7) | 20-17 | Lost 2 |
| » W: Gary Lavelle (3-0) L: Bo McLaughlin (1-1) | Second | 1½ out |
| Thursday, May 17 |
| » Lost to Giants (19-18), 3-0 | Astrodome (11-8) | 20-18 | Lost 3 |
| » W: Ed Halicki (4-3) L: Ken Forsch (4-3) | Second | 2 out |
| Friday, May 18 |
| » Defeated Padres (15-24), 3-2 | Astrodome (12-8) | 21-18 | |
| » W: Joe Niekro (4-2) L: Rollie Fingers (2-3) | Second | 2 out |
| Saturday, May 19 |
| » Lost to Padres (16-24), 4-2 | Astrodome (12-9) | 21-19 | |
| » W: Rollie Fingers (3-3) L: J.R. Richard (4-4) | Second | 3 out |
| Sunday, May 20 |
| » Defeated Padres (16-25), 1-0 | Astrodome (13-9) | 22-19 | |
| » W: Rick Williams (1-1) L: Gaylord Perry (3-4) | Second | 1½ out |
| » Defeated Padres (16-26), 6-3 | Astrodome (14-9) | 23-19 | Won 2 |
| » W: Joaquin Andujar (4-1) L: John D'Acquisto (2-4) | Second | 1½ out |
| » Major-league debuts: Randy Niemann (Astros) |
| Monday, May 21 |
| » Lost to Braves (14-25), 7-5 | Atlanta-Fulton County Stadium (0-1) | 23-20 | |
| » W: Phil Niekro (5-6) L: Bo McLaughlin (1-2) S: Gene Garber (8) | Third | 2 out |
| Tuesday, May 22 |
| » Defeated Braves (14-26), 4-1 | Atlanta-Fulton County Stadium (1-1) | 24-20 | |
| » W: Joe Niekro (5-2) L: Mickey Mahler (1-4) | Third | 2 out |
| Wednesday, May 23 |
| » Lost to Braves (15-26), 6-5 | Atlanta-Fulton County Stadium (1-2) | 24-21 | |
| » W: Tony Brizzolara (1-0) L: Joaquin Andujar (4-2) S: Gene Garber (9) | Third | 2 out |
| Future Astro Kirk Saarloos is born in Long Beach, CA. |
| Friday, May 25 |
| » Lost to Padres (19-27), 2-1 | San Diego/Jack Murphy Stadium (0-1) | 24-22 | Lost 2 |
| » W: Rollie Fingers (5-3) L: Joe Sambito (2-2) | Third | 1½ out |
| Saturday, May 26 |
| » Defeated Padres (19-28), 9-0 | San Diego/Jack Murphy Stadium (1-1) | 25-22 | |
| » W: Joe Niekro (6-2) L: Mickey Lolich (0-2) | Third | 1½ out |
| Sunday, May 27 |
| » Defeated Padres (19-29), 4-2 | San Diego/Jack Murphy Stadium (2-1) | 26-22 | Won 2 |
| » W: J.R. Richard (5-4) L: Eric Rasmussen (1-5) | Second | 1½ out |
| Monday, May 28 |
| » Lost to Padres (20-29), 5-4 | San Diego/Jack Murphy Stadium (2-2) | 26-23 | |
| » W: Randy Jones (5-3) L: Joaquin Andujar (4-3) S: Rollie Fingers (6) | Second | 1½ out |
| » Major-league debuts: Bert Roberge (Astros) |
| Tuesday, May 29 |
| » Defeated Reds (26-21), 2-1 | Astrodome (15-9) | 27-23 | |
| » W: Randy Niemann (1-0) L: Paul Moskau (4-2) | Second | 1½ out |
| Wednesday, May 30 |
| » Defeated Reds (26-22), 6-3 | Astrodome (16-9) | 28-23 | Won 2 |
| » W: Joe Niekro (7-2) L: Tom Seaver (2-4) S: Joe Sambito (4) | First | -- |
| Thursday, May 31 |
| » Defeated Reds (26-23), 3-0 | Astrodome (17-9) | 29-23 | Won 3 |
| » W: Rick Williams (2-1) L: Fred Norman (2-5) | First | -- |
| Friday, June 1 |
| » Defeated Expos (29-16), 3-2 | Astrodome (18-9) | 30-23 | Won 4 |
| » W: J.R. Richard (6-4) L: Ross Grimsley (4-4) | First | -- |
| Saturday, June 2 |
| » Defeated Expos (29-17), 2-1 | Astrodome (19-9) | 31-23 | Won 5 |
| » W: Joaquin Andujar (5-3) L: Elias Sosa (3-2) | First | -- |
| Sunday, June 3 |
| » Defeated Expos (29-18), 5-4 | Astrodome (20-9) | 32-23 | Won 6 |
| » W: Joe Niekro (8-2) L: Steve Rogers (5-3) S: Bert Roberge (1) | First | -- |
| Monday, June 4 |
| » Defeated Phillies (28-24), 3-0 | Astrodome (21-9) | 33-23 | Won 7 |
| » W: Randy Niemann (2-0) L: Larry Christenson (0-3) | First | -- |
| Tuesday, June 5 |
| » Lost to Phillies (29-24), 8-0 | Astrodome (21-10) | 33-24 | |
| » W: Steve Carlton (7-6) L: Rick Williams (2-2) | First | -- |
| Wednesday, June 6 |
| » Defeated Phillies (29-25), 4-3 | Astrodome (22-10) | 34-24 | |
| » W: Joe Sambito (3-2) L: Ron Reed (5-2) S: Bert Roberge (2) | First | -- |
| Friday, June 8 |
| » Defeated Mets (20-31), 5-0 | Shea Stadium (1-0) | 35-24 | Won 2 |
| » W: Joe Niekro (9-2) L: Pat Zachry (5-1) | First | -- |
| Saturday, June 9 |
| » Lost to Mets (21-31), 4-0 | Shea Stadium (1-1) | 35-25 | |
| » W: Craig Swan (6-4) L: Joaquin Andujar (5-4) | First | -- |
| Sunday, June 10 |
| » Defeated Mets (21-32), 5-3 | Shea Stadium (2-1) | 36-25 | |
| » W: George Throop (1-0) L: Kevin Kobel (2-2) S: Joe Sambito (5) | First | -- |
| Monday, June 11 |
| » Lost to Phillies (31-27), 4-2 | Veteran's Stadium (0-1) | 36-26 | |
| » W: Randy Lerch (3-4) L: J.R. Richard (6-5) | First | -- |
| Tuesday, June 12 |
| » Lost to Phillies (32-27), 4-0 | Veteran's Stadium (0-2) | 36-27 | Lost 2 |
| » W: Nino Espinosa (6-5) L: Rick Williams (2-3) | First | -- |
| Wednesday, June 13 |
| » Defeated Phillies (32-28), 4-3 | Veteran's Stadium (1-2) | 37-27 | |
| » W: Joe Niekro (10-2) L: Dick Ruthven (6-4) | First | -- |
| Friday, June 15 |
| » Defeated Expos (34-23), 2-1 | Stade Olympique (1-0) | 38-27 | Won 2 |
| » W: Joaquin Andujar (6-4) L: Elias Sosa (4-4) | First | -- |
| Saturday, June 16 |
| » Lost to Expos (35-23), 4-2 | Stade Olympique (1-1) | 38-28 | |
| » W: Ross Grimsley (6-4) L: J.R. Richard (6-6) S: Elias Sosa (6) | First | -- |
| Sunday, June 17 |
| » Lost to Expos (36-23), 19-3 | Stade Olympique (1-2) | 38-29 | Lost 2 |
| » W: Dan Schatzeder (2-1) L: Joe Niekro (10-3) | First | -- |
| Monday, June 18 |
| » Defeated Mets (26-34), 3-2 | Astrodome (23-10) | 39-29 | |
| » W: Bert Roberge (1-0) L: Tom Hausman (0-2) | First | -- |
| Tuesday, June 19 |
| » Defeated Mets (26-35), 3-1 | Astrodome (24-10) | 40-29 | Won 2 |
| » W: Joaquin Andujar (7-4) L: Andy Hassler (1-3) | First | -- |
| Wednesday, June 20 |
| » Defeated Mets (26-36), 5-4 | Astrodome (25-10) | 41-29 | Won 3 |
| » W: Joe Sambito (4-2) L: Craig Swan (7-5) | First | -- |
| Friday, June 22 |
| » Defeated Padres (32-40), 2-1 | Astrodome (26-10) | 42-29 | Won 4 |
| » W: Joe Niekro (11-3) L: Bob Shirley (2-7) S: Joe Sambito (6) | First | -- |
| Saturday, June 23 |
| » Defeated Padres (32-41), 3-2 | Astrodome (27-10) | 43-29 | Won 5 |
| » W: Tom Dixon (1-1) L: Rollie Fingers (6-4) | First | -- |
| Sunday, June 24 |
| » Defeated Padres (32-42), 4-1 | Astrodome (28-10) | 44-29 | Won 6 |
| » W: Joaquin Andujar (8-4) L: Eric Rasmussen (3-8) | First | -- |
| Monday, June 25 |
| » Lost to Reds (38-34), 2-1 | Astrodome (28-11) | 44-30 | |
| » W: Tom Seaver (5-5) L: J.R. Richard (6-7) S: Doug Bair (10) | First | -- |
| » Defeated Reds (38-35), 4-0 | Astrodome (29-11) | 45-30 | |
| » W: Randy Niemann (3-0) L: Mike LaCoss (8-2) | First | -- |
| Tuesday, June 26 |
| » Defeated Reds (38-36), 6-5 | Astrodome (30-11) | 46-30 | Won 2 |
| » W: Bert Roberge (2-0) L: Doug Bair (4-3) S: Joe Sambito (7) | First | -- |
| Wednesday, June 27 |
| » Lost to Giants (37-37), 6-3 | Candlestick Park (2-3) | 46-31 | |
| » W: Greg Minton (1-0) L: Tom Dixon (1-2) S: Dave Roberts (3) | First | -- |
| Thursday, June 28 |
| » Defeated Giants (37-38), 6-5 | Candlestick Park (3-3) | 47-31 | |
| » W: Rick Williams (3-3) L: John Curtis (3-4) S: Randy Niemann (1) | First | -- |
| » Major-league debuts: Joe Strain (Giants) |
| Friday, June 29 |
| » Defeated Padres (35-45), 4-1 | San Diego/Jack Murphy Stadium (3-2) | 48-31 | Won 2 |
| » W: Joaquin Andujar (9-4) L: Gaylord Perry (7-6) | First | -- |
| Saturday, June 30 |
| » Defeated Padres (35-46), 3-0 | San Diego/Jack Murphy Stadium (4-2) | 49-31 | Won 3 |
| » W: J.R. Richard (7-7) L: Bob Shirley (3-8) | First | -- |
| Sunday, July 1 |
| » Defeated Padres (35-47), 4-1 | San Diego/Jack Murphy Stadium (5-2) | 50-31 | Won 4 |
| » W: Joe Niekro (12-3) L: Randy Jones (6-6) S: Joe Sambito (8) | First | -- |
| Tuesday, July 3 |
| » Defeated Reds (41-40), 3-2 | Riverfront Stadium (2-3) | 51-31 | Won 5 |
| » W: Ken Forsch (5-3) L: Doug Bair (4-4) | First | -- |
| Wednesday, July 4 |
| » Defeated Reds (41-41), 3-2 | Riverfront Stadium (3-3) | 52-31 | Won 6 |
| » W: Joaquin Andujar (10-4) L: Bill Bonham (3-2) S: Joe Sambito (9) | First | -- |
| Thursday, July 5 |
| » Lost to Reds (42-41), 5-4 | Riverfront Stadium (3-4) | 52-32 | |
| » W: Tom Seaver (7-5) L: J.R. Richard (7-8) S: Doug Bair (12) | First | -- |
| Friday, July 6 |
| » Defeated Cubs (40-36), 4-2 | Wrigley Field (2-1) | 53-32 | |
| » W: Joe Niekro (13-3) L: Lynn McGlothen (9-7) S: Joe Sambito (10) | First | -- |
| Saturday, July 7 |
| » Lost to Cubs (41-36), 6-0 | Wrigley Field (2-2) | 53-33 | |
| » W: Ken Holtzman (6-6) L: Rick Williams (3-4) | First | -- |
| » Lost to Cubs (42-36), 8-3 | Wrigley Field (2-3) | 53-34 | Lost 2 |
| » W: Dennis Lamp (6-4) L: Randy Niemann (3-1) | First | -- |
| Sunday, July 8 |
| » Lost to Cubs (43-36), 10-0 | Wrigley Field (2-4) | 53-35 | Lost 3 |
| » W: Mike Krukow (6-5) L: Ken Forsch (5-4) S: Donnie Moore (1) | First | -- |
| Tuesday, July 10 |
| » Lost to Pirates (42-38), 4-3 | Astrodome (30-12) | 53-36 | Lost 4 |
| » W: Jim Bibby (4-2) L: Joaquin Andujar (10-5) S: Kent Tekulve (12) | First | -- |
| Wednesday, July 11 |
| » Lost to Pirates (43-38), 5-1 | Astrodome (30-13) | 53-37 | Lost 5 |
| » W: Bruce Kison (5-4) L: J.R. Richard (7-9) | First | -- |
| Thursday, July 12 |
| » Lost to Pirates (44-38), 5-3 | Astrodome (30-14) | 53-38 | Lost 6 |
| » W: Bert Blyleven (7-3) L: Joe Niekro (13-4) S: Kent Tekulve (13) | First | -- |
| Friday, July 13 |
| » Lost to Cardinals (43-41), 1-0 | Astrodome (30-15) | 53-39 | Lost 7 |
| » W: Silvio Martinez (7-3) L: Ken Forsch (5-5) | First | -- |
| Saturday, July 14 |
| » Defeated Cardinals (43-42), 3-2 | Astrodome (31-15) | 54-39 | |
| » W: Joaquin Andujar (11-5) L: Pete Vuckovich (8-6) S: Joe Sambito (11) | First | -- |
| Sunday, July 15 |
| » Lost to Cardinals (44-42), 3-1 | Astrodome (31-16) | 54-40 | |
| » W: John Fulgham (3-2) L: J.R. Richard (7-10) | First | -- |
| Thursday, July 19 |
| » Lost to Pirates (47-39), 9-5 | Three Rivers Stadium (1-2) | 54-41 | Lost 2 |
| » W: Dave Roberts (1-2) L: Ken Forsch (5-6) | First | -- |
| » Lost to Pirates (48-39), 4-2 | Three Rivers Stadium (1-3) | 54-42 | Lost 3 |
| » W: Bruce Kison (6-4) L: Joe Niekro (13-5) S: Grant Jackson (11) | First | -- |
| Friday, July 20 |
| » Lost to Pirates (49-39), 9-3 | Three Rivers Stadium (1-4) | 54-43 | Lost 4 |
| » W: John Candelaria (9-7) L: J.R. Richard (7-11) | First | -- |
| Saturday, July 21 |
| » Lost to Pirates (50-39), 6-5 | Three Rivers Stadium (1-5) | 54-44 | Lost 5 |
| » W: Enrique Romo (5-3) L: Joe Sambito (4-3) S: Kent Tekulve (14) | First | -- |
| Sunday, July 22 |
| » Defeated Cardinals (45-45), 7-6 | Busch Stadium II (3-2) | 55-44 | |
| » W: Joe Sambito (5-3) L: Will McEnaney (0-1) | First | -- |
| Monday, July 23 |
| » Defeated Cardinals (45-46), 3-2 | Busch Stadium II (4-2) | 56-44 | Won 2 |
| » W: Joe Niekro (14-5) L: John Fulgham (3-3) | First | -- |
| Tuesday, July 24 |
| » Defeated Cubs (52-41), 6-1 | Astrodome (32-16) | 57-44 | Won 3 |
| » W: Ken Forsch (6-6) L: Dennis Lamp (7-6) | First | -- |
| Wednesday, July 25 |
| » Defeated Cubs (52-42), 6-4 | Astrodome (33-16) | 58-44 | Won 4 |
| » W: J.R. Richard (8-11) L: Rick Reuschel (9-7) S: Joe Sambito (12) | First | -- |
| Thursday, July 26 |
| » Lost to Dodgers (43-58), 6-5 | Astrodome (33-17) | 58-45 | |
| » W: Joe Beckwith (1-0) L: Joaquin Andujar (11-6) S: Terry Forster (2) | First | -- |
| Friday, July 27 |
| » Lost to Dodgers (44-58), 11-7 | Astrodome (33-18) | 58-46 | Lost 2 |
| » W: Charlie Hough (2-2) L: Joe Niekro (14-6) | First | -- |
| Saturday, July 28 |
| » Defeated Dodgers (44-59), 5-2 | Astrodome (34-18) | 59-46 | |
| » W: Ken Forsch (7-6) L: Jerry Reuss (3-9) | First | -- |
| Sunday, July 29 |
| » Defeated Dodgers (44-60), 4-3 | Astrodome (35-18) | 60-46 | Won 2 |
| » W: J.R. Richard (9-11) L: Terry Forster (1-2) | First | -- |
| Monday, July 30 |
| » Lost to Giants (52-54), 8-0 | Astrodome (35-19) | 60-47 | |
| » W: Bob Knepper (8-5) L: Joaquin Andujar (11-7) | First | -- |
| Tuesday, July 31 |
| » Defeated Giants (52-55), 6-4 | Astrodome (36-19) | 61-47 | |
| » W: Joe Niekro (15-6) L: Ed Whitson (4-6) S: Bert Roberge (3) | First | -- |
| Wednesday, August 1 |
| » Defeated Giants (52-56), 5-4 | Astrodome (37-19) | 62-47 | Won 2 |
| » W: Ken Forsch (8-6) L: Vida Blue (8-9) S: Bert Roberge (4) | First | -- |
| Friday, August 3 |
| » Defeated Braves (45-65), 4-1 | Astrodome (38-19) | 63-47 | Won 3 |
| » W: J.R. Richard (10-11) L: Rick Matula (6-8) | First | -- |
| Saturday, August 4 |
| » Defeated Braves (45-66), 4-3 | Astrodome (39-19) | 64-47 | Won 4 |
| » W: Joe Sambito (6-3) L: Gene Garber (5-12) | First | -- |
| » Defeated Braves (45-67), 6-2 | Astrodome (40-19) | 65-47 | Won 5 |
| » W: Frank LaCorte (1-0) L: Phil Niekro (14-14) S: Joe Sambito (13) | First | -- |
| Sunday, August 5 |
| » Defeated Braves (45-68), 3-2 | Astrodome (41-19) | 66-47 | Won 6 |
| » W: Bert Roberge (3-0) L: Gene Garber (5-13) S: Joe Sambito (14) | First | -- |
| Tuesday, August 7 |
| » Lost to Dodgers (49-63), 10-8 | Dodger Stadium (2-2) | 66-48 | |
| » W: Ken Brett (3-2) L: Joe Sambito (6-4) S: Dave Patterson (4) | First | -- |
| Wednesday, August 8 |
| » Defeated Dodgers (49-64), 4-1 | Dodger Stadium (3-2) | 67-48 | |
| » W: J.R. Richard (11-11) L: Burt Hooton (10-8) | First | -- |
| Thursday, August 9 |
| » Lost to Dodgers (50-64), 4-3 | Dodger Stadium (3-3) | 67-49 | |
| » W: Rick Sutcliffe (10-8) L: Joaquin Andujar (11-8) S: Joe Beckwith (1) | First | -- |
| Friday, August 10 |
| » Defeated Braves (46-72), 2-1 | Atlanta-Fulton County Stadium (2-2) | 68-49 | |
| » W: Joe Niekro (16-6) L: Eddie Solomon (4-9) S: Joe Sambito (15) | First | -- |
| Sunday, August 12 |
| » Lost to Braves (47-72), 3-2 | Atlanta-Fulton County Stadium (2-3) | 68-50 | |
| » W: Phil Niekro (15-15) L: Rick Williams (3-5) | First | -- |
| » Major-league debuts: Alan Knicely (Astros) |
| Monday, August 13 |
| » Defeated Expos (63-50), 4-1 | Astrodome (42-19) | 69-50 | |
| » W: J.R. Richard (12-11) L: Steve Rogers (10-7) | First | -- |
| Tuesday, August 14 |
| » Defeated Expos (63-51), 2-1 | Astrodome (43-19) | 70-50 | Won 2 |
| » W: Joaquin Andujar (12-8) L: Bill Lee (10-10) | First | -- |
| Wednesday, August 15 |
| » Lost to Expos (64-51), 3-0 | Astrodome (43-20) | 70-51 | |
| » W: Dan Schatzeder (8-4) L: Joe Niekro (16-7) S: Scott Sanderson (1) | First | -- |
| Friday, August 17 |
| » Lost to Phillies (62-59), 5-2 | Astrodome (43-21) | 70-52 | Lost 2 |
| » W: Randy Lerch (7-11) L: Frank LaCorte (1-1) | First | -- |
| » Major-league debuts: Pete Ladd (Astros) |
| Saturday, August 18 |
| » Lost to Phillies (63-59), 1-0 | Astrodome (43-22) | 70-53 | Lost 3 |
| » W: Larry Christenson (4-8) L: J.R. Richard (12-12) S: Ron Reed (4) | First | -- |
| Sunday, August 19 |
| » Lost to Phillies (64-59), 3-2 | Astrodome (43-23) | 70-54 | Lost 4 |
| » W: Steve Carlton (12-10) L: Joaquin Andujar (12-9) | First | -- |
| Monday, August 20 |
| » Defeated Mets (51-70), 8-1 | Shea Stadium (3-1) | 71-54 | |
| » W: Joe Niekro (17-7) L: Craig Swan (12-10) | First | -- |
| Tuesday, August 21 |
| » Lost to Mets (52-70), 5-0 | Shea Stadium (3-2) | 71-55 | |
| » W: Pete Falcone (5-9) L: Frank LaCorte (1-2) | First | -- |
| Wednesday, August 22 |
| » Defeated Mets (52-71), 3-1 | Shea Stadium (4-2) | 72-55 | |
| » W: J.R. Richard (13-12) L: Kevin Kobel (5-7) | First | -- |
| Friday, August 24 |
| » Lost to Phillies (65-62), 5-3 | Veteran's Stadium (1-3) | 72-56 | |
| » W: Steve Carlton (13-10) L: Joaquin Andujar (12-10) | First | -- |
| Saturday, August 25 |
| » Defeated Phillies (65-63), 3-1 | Veteran's Stadium (2-3) | 73-56 | |
| » W: Joe Niekro (18-7) L: Nino Espinosa (13-10) S: Joe Sambito (16) | First | -- |
| Sunday, August 26 |
| » Defeated Phillies (65-64), 4-1 | Veteran's Stadium (3-3) | 74-56 | Won 2 |
| » W: Pete Ladd (1-0) L: Kevin Saucier (1-2) S: Joe Sambito (17) | First | -- |
| Monday, August 27 |
| » Defeated Expos (69-54), 3-0 | Stade Olympique (2-2) | 75-56 | Won 3 |
| » W: J.R. Richard (14-12) L: Rudy May (7-2) | First | -- |
| Tuesday, August 28 |
| » Lost to Expos (70-54), 7-6 | Stade Olympique (2-3) | 75-57 | |
| » W: David Palmer (6-2) L: Pete Ladd (1-1) | Second | ½ out |
| Wednesday, August 29 |
| » Lost to Expos (71-54), 5-3 | Stade Olympique (2-4) | 75-58 | Lost 2 |
| » W: Bill Lee (13-10) L: Joe Niekro (18-8) S: Elias Sosa (15) | Second | 1½ out |
| Friday, August 31 |
| » Defeated Mets (52-78), 2-0 | Astrodome (44-23) | 76-58 | |
| » W: Ken Forsch (9-6) L: Craig Swan (12-11) S: Joe Sambito (18) | Second | ½ out |
| » Major-league debuts: Danny Heep (Astros) |
| Saturday, September 1 |
| » Defeated Mets (52-79), 3-1 | Astrodome (45-23) | 77-58 | Won 2 |
| » W: J.R. Richard (15-12) L: Pete Falcone (5-11) | First | -- |
| Sunday, September 2 |
| » Lost to Mets (53-79), 5-4 | Astrodome (45-24) | 77-59 | |
| » W: Kevin Kobel (6-8) L: Randy Niemann (3-2) S: Neil Allen (6) | First | -- |
| Monday, September 3 |
| » Lost to Dodgers (65-72), 1-0 | Astrodome (45-25) | 77-60 | Lost 2 |
| » W: Jerry Reuss (5-12) L: Joe Niekro (18-9) | Second | ½ out |
| Tuesday, September 4 |
| » Defeated Dodgers (65-73), 9-4 | Astrodome (46-25) | 78-60 | |
| » W: Rick Williams (4-5) L: Joe Beckwith (1-1) S: Joaquin Andujar (4) | First | -- |
| Wednesday, September 5 |
| » Defeated Padres (58-82), 4-3 | Astrodome (47-25) | 79-60 | Won 2 |
| » W: Joe Sambito (7-4) L: John D'Acquisto (9-13) | First | -- |
| Thursday, September 6 |
| » Defeated Padres (58-83), 2-0 | Astrodome (48-25) | 80-60 | Won 3 |
| » W: J.R. Richard (16-12) L: Bob Owchinko (4-10) | First | -- |
| Friday, September 7 |
| » Lost to Giants (62-80), 9-2 | Astrodome (48-26) | 80-61 | |
| » W: Vida Blue (11-13) L: Joaquin Andujar (12-11) | First | -- |
| Saturday, September 8 |
| » Lost to Giants (63-80), 2-1 | Astrodome (48-27) | 80-62 | Lost 2 |
| » W: Greg Minton (2-2) L: Joe Sambito (7-5) S: Gary Lavelle (17) | Second | ½ out |
| Sunday, September 9 |
| » Defeated Giants (63-81), 4-1 | Astrodome (49-27) | 81-62 | |
| » W: Ken Forsch (10-6) L: Greg Minton (2-3) S: Joe Sambito (19) | First | -- |
| Tuesday, September 11 |
| » Lost to Reds (82-63), 9-8 | Riverfront Stadium (3-5) | 81-63 | |
| » W: Tom Hume (10-8) L: Joe Sambito (7-6) | Second | ½ out |
| Wednesday, September 12 |
| » Lost to Reds (83-63), 7-4 | Riverfront Stadium (3-6) | 81-64 | Lost 2 |
| » W: Frank Pastore (4-6) L: Joe Niekro (18-10) S: Tom Hume (15) | Second | 1½ out |
| Friday, September 14 |
| » Defeated Giants (64-84), 7-0 | Candlestick Park (4-3) | 82-64 | |
| » W: Vern Ruhle (2-3) L: Ed Halicki (5-6) | Second | ½ out |
| Saturday, September 15 |
| » Lost to Giants (65-84), 5-3 | Candlestick Park (4-4) | 82-65 | |
| » W: Pedro Borbon (6-5) L: Joaquin Andujar (12-12) S: Greg Minton (2) | Second | 1½ out |
| Sunday, September 16 |
| » Lost to Giants (66-84), 2-1 | Candlestick Park (4-5) | 82-66 | Lost 2 |
| » W: Greg Minton (3-3) L: J.R. Richard (16-13) | Second | 2½ out |
| Monday, September 17 |
| » Defeated Padres (62-88), 1-0 | San Diego/Jack Murphy Stadium (6-2) | 83-66 | |
| » W: Joe Niekro (19-10) L: Bob Owchinko (5-11) | Second | 1½ out |
| Tuesday, September 18 |
| » Lost to Padres (63-88), 4-0 | San Diego/Jack Murphy Stadium (6-3) | 83-67 | |
| » W: Eric Rasmussen (5-9) L: Rick Williams (4-6) | Second | 1½ out |
| Wednesday, September 19 |
| » Lost to Braves (60-90), 6-5 | Astrodome (49-28) | 83-68 | Lost 2 |
| » W: Bo McLaughlin (2-3) L: Vern Ruhle (2-4) S: Gene Garber (24) | Second | 2½ out |
| Thursday, September 20 |
| » Defeated Braves (60-91), 7-1 | Astrodome (50-28) | 84-68 | |
| » W: Ken Forsch (11-6) L: Tommy Boggs (0-1) | Second | 2½ out |
| Friday, September 21 |
| » Defeated Reds (87-67), 3-2 | Astrodome (51-28) | 85-68 | Won 2 |
| » W: Joe Sambito (8-6) L: Tom Hume (10-9) | Second | 1½ out |
| Saturday, September 22 |
| » Defeated Reds (87-68), 4-1 | Astrodome (52-28) | 86-68 | Won 3 |
| » W: Joe Niekro (20-10) L: Mike LaCoss (14-8) S: Joe Sambito (20) | Second | ½ out |
| Sunday, September 23 |
| » Lost to Reds (88-68), 7-1 | Astrodome (52-29) | 86-69 | |
| » W: Frank Pastore (5-7) L: Vern Ruhle (2-5) | Second | 1½ out |
| Monday, September 24 |
| » Lost to Braves (62-92), 5-4 | Atlanta-Fulton County Stadium (2-4) | 86-70 | Lost 2 |
| » W: Mickey Mahler (5-11) L: Joe Sambito (8-7) | Second | 2½ out |
| » Lost to Braves (63-92), 8-1 | Atlanta-Fulton County Stadium (2-5) | 86-71 | Lost 3 |
| » W: Eddie Solomon (7-13) L: Rick Williams (4-7) | Second | 2½ out |
| Tuesday, September 25 |
| » Defeated Braves (63-93), 8-0 | Atlanta-Fulton County Stadium (3-5) | 87-71 | |
| » W: J.R. Richard (17-13) L: Tommy Boggs (0-2) | Second | 1½ out |
| Wednesday, September 26 |
| » Lost to Braves (64-93), 9-4 | Atlanta-Fulton County Stadium (3-6) | 87-72 | |
| » W: Phil Niekro (20-20) L: Joe Niekro (20-11) | Second | 2½ out |
| Friday, September 28 |
| » Lost to Dodgers (79-81), 6-5 | Dodger Stadium (3-4) | 87-73 | Lost 2 |
| » W: Charlie Hough (7-5) L: Vern Ruhle (2-6) S: Bobby Castillo (7) | Second | 3½ out |
| Saturday, September 29 |
| » Defeated Dodgers (79-82), 3-0 | Dodger Stadium (4-4) | 88-73 | |
| » W: J.R. Richard (18-13) L: Jerry Reuss (7-14) S: Joe Sambito (21) | Second | 2½ out |
| Sunday, September 30 |
| » Defeated Dodgers (79-83), 3-2 | Dodger Stadium (5-4) | 89-73 | Won 2 |
| » W: Joe Niekro (21-11) L: Rick Sutcliffe (17-10) S: Joe Sambito (22) | Second | 1½ out |
Game information provided by Retrosheet (www.retrosheet.org) |