| Tuesday, January 19 |
| Future Astro Jeff Juden is born in Salem, MA. Future Astro Phil Nevin is born in Fullerton, CA. |
| Friday, March 5 |
| Future Astro Brian Hunter is born in Portland, OR. |
| Monday, April 5 |
| » Defeated Dodgers (0-1), 5-2 | Astrodome (1-0) | 1-0 | |
| » Starters: Bill Singer vs Larry Dierker | First | -- |
| Tuesday, April 6 |
| » Lost to Dodgers (1-1), 2-0 | Astrodome (1-1) | 1-1 | |
| » Starters: Claude Osteen vs Don Wilson | Second | ½ out |
| Wednesday, April 7 |
| » Defeated Dodgers (1-2), 2-1 | Astrodome (2-1) | 2-1 | |
| » Starters: Don Sutton vs Wade Blasingame | Second | ½ out |
| Thursday, April 8 |
| » Defeated Cubs (1-2), 7-3 | Astrodome (3-1) | 3-1 | Won 2 |
| » Starters: Ken Holtzman vs Jack Billingham | Second | 1 out |
| Friday, April 9 |
| » Lost to Cubs (2-2), 6-0 | Astrodome (3-2) | 3-2 | |
| » Starters: Milt Pappas vs Tom Griffin | Second | 1 out |
| Saturday, April 10 |
| » Defeated Cubs (2-3), 2-1 | Astrodome (4-2) | 4-2 | |
| » Starters: Fergie Jenkins vs Larry Dierker | Second | 1 out |
| Sunday, April 11 |
| » Defeated Cubs (2-4), 7-4 | Astrodome (5-2) | 5-2 | Won 2 |
| » Starters: Bill Hands vs Don Wilson | Second | 1 out |
| Monday, April 12 |
| » Lost to Cardinals (3-3), 5-4 | Busch Stadium II (0-1) | 5-3 | |
| » Starters: Wade Blasingame vs Steve Carlton | Third | ½ out |
| Tuesday, April 13 |
| » Defeated Cardinals (3-4), 8-4 | Busch Stadium II (1-1) | 6-3 | |
| » Starters: Jack Billingham vs Mike Torrez | Second | 1 out |
| Wednesday, April 14 |
| » Lost to Giants (6-2), 2-1 | Candlestick Park (0-1) | 6-4 | |
| » Starters: Tom Griffin vs Steve Stone | Second | 1 out |
| Thursday, April 15 |
| » Lost to Giants (7-2), 4-3 | Candlestick Park (0-2) | 6-5 | Lost 2 |
| » Starters: Larry Dierker vs Frank Reberger | Second | 2 out |
| Friday, April 16 |
| » Lost to Dodgers (5-6), 6-5 | Dodger Stadium (0-1) | 6-6 | Lost 3 |
| » Starters: Don Wilson vs Sandy Vance | Third | 3 out |
| Saturday, April 17 |
| » Defeated Dodgers (5-7), 5-3 | Dodger Stadium (1-1) | 7-6 | |
| » Starters: Wade Blasingame vs Bill Singer | Third | 3 out |
| Sunday, April 18 |
| » Defeated Dodgers (5-8), 8-6 | Dodger Stadium (2-1) | 8-6 | Won 2 |
| » Starters: Jack Billingham vs Claude Osteen | Third | 3½ out |
| Tuesday, April 20 |
| » Lost to Cubs (5-9), 3-1 | Wrigley Field (0-1) | 8-7 | |
| » Starters: Tom Griffin vs Fergie Jenkins | Third | 4 out |
| » Major-league debuts: Rich Chiles (Astros) |
| Thursday, April 22 |
| » Defeated Cubs (5-10), 6-1 | Wrigley Field (1-1) | 9-7 | |
| » Starters: Larry Dierker vs Bill Hands | Third | 3 out |
| Friday, April 23 |
| » Lost to Expos (6-4), 3-2 | Astrodome (5-3) | 9-8 | |
| » Starters: Carl Morton vs Don Wilson | Third | 4 out |
| Saturday, April 24 |
| » Lost to Expos (7-4), 3-2 | Astrodome (5-4) | 9-9 | Lost 2 |
| » Starters: Steve Renko vs Wade Blasingame | Fourth | 5 out |
| Sunday, April 25 |
| » Lost to Expos (8-4), 2-1 | Astrodome (5-5) | 9-10 | Lost 3 |
| » Starters: Bill Stoneman vs Jack Billingham | Fourth | 5 out |
| Monday, April 26 |
| » Lost to Phillies (6-10), 2-1 | Astrodome (5-6) | 9-11 | Lost 4 |
| » Starters: Rick Wise vs Tom Griffin | Fourth | 5½ out |
| Tuesday, April 27 |
| » Defeated Phillies (6-11), 1-0 | Astrodome (6-6) | 10-11 | |
| » Starters: Jim Bunning vs Larry Dierker | Fourth | 5½ out |
| Wednesday, April 28 |
| » Defeated Phillies (6-12), 4-3 | Astrodome (7-6) | 11-11 | Won 2 |
| » Starters: Barry Lersch vs Don Wilson | Third | 5½ out |
| Friday, April 30 |
| » Lost to Mets (12-7), 4-3 | Astrodome (7-7) | 11-12 | |
| » Starters: Jim McAndrew vs Tom Griffin | Third | 7 out |
| Saturday, May 1 |
| » Defeated Mets (12-8), 3-1 | Astrodome (8-7) | 12-12 | |
| » Starters: Tom Seaver vs Larry Dierker | Fourth | 6 out |
| Sunday, May 2 |
| » Lost to Mets (13-8), 6-5 | Astrodome (8-8) | 12-13 | |
| » Starters: Jerry Koosman vs Don Wilson | Fourth | 7 out |
| Wednesday, May 5 |
| » Lost to Expos (10-7), 5-1 | Parc Jarry (0-1) | 12-14 | Lost 2 |
| » Starters: Wade Blasingame vs Bill Stoneman | Fourth | 7½ out |
| Thursday, May 6 |
| » Defeated Expos (10-8), 5-2 | Parc Jarry (1-1) | 13-14 | |
| » Starters: Larry Dierker vs Steve Renko | Fourth | 7 out |
| Friday, May 7 |
| » Defeated Phillies (8-17), 8-1 | Veteran's Stadium (1-0) | 14-14 | Won 2 |
| » Starters: Don Wilson vs Jim Bunning | Second | 7 out |
| Sunday, May 9 |
| » Lost to Phillies (9-17), 2-1 | Veteran's Stadium (1-1) | 14-15 | |
| » Starters: Jack Billingham vs Barry Lersch | Third | 7 out |
| Monday, May 10 |
| » Lost to Mets (18-9), 2-1 | Shea Stadium (0-1) | 14-16 | Lost 2 |
| » Starters: Wade Blasingame vs Gary Gentry | Fourth | 8 out |
| Future Astro Glen Barker is born in Albany, NY. |
| Tuesday, May 11 |
| » Lost to Mets (19-9), 8-1 | Shea Stadium (0-2) | 14-17 | Lost 3 |
| » Starters: Larry Dierker vs Nolan Ryan | Fourth | 9 out |
| Wednesday, May 12 |
| » Defeated Mets (19-10), 5-4 | Shea Stadium (1-2) | 15-17 | |
| » Starters: Don Wilson vs Tom Seaver | Third | 9 out |
| Friday, May 14 |
| » Lost to Cardinals (19-14), 4-2 | Astrodome (8-9) | 15-18 | |
| » Starters: Bob Gibson vs Jack Billingham | Fourth | 10 out |
| Saturday, May 15 |
| » Lost to Cardinals (20-14), 6-5 | Astrodome (8-10) | 15-19 | Lost 2 |
| » Starters: Steve Carlton vs Wade Blasingame | Fourth | 11 out |
| Sunday, May 16 |
| » Defeated Cardinals (20-15), 12-4 | Astrodome (9-10) | 16-19 | |
| » Starters: Jerry Reuss vs Larry Dierker | Fourth | 10 out |
| Monday, May 17 |
| » Defeated Padres (10-26), 2-0 | Astrodome (10-10) | 17-19 | Won 2 |
| » Starters: Dave Roberts vs Don Wilson | Fourth | 9½ out |
| Tuesday, May 18 |
| » Defeated Padres (10-27), 3-2 | Astrodome (11-10) | 18-19 | Won 3 |
| » Starters: Steve Arlin vs Ken Forsch | Third | 9½ out |
| Wednesday, May 19 |
| » Lost to Padres (11-27), 2-1 | Astrodome (11-11) | 18-20 | |
| » Starters: Tom Phoebus vs Jack Billingham | Fourth | 9½ out |
| Thursday, May 20 |
| » Lost to Padres (12-27), 4-2 | Astrodome (11-12) | 18-21 | Lost 2 |
| » Starters: Clay Kirby vs Wade Blasingame | Fourth | 10½ out |
| Friday, May 21 |
| » Defeated Giants (29-12), 4-1 | Astrodome (12-12) | 19-21 | |
| » Starters: Gaylord Perry vs Larry Dierker | Fourth | 9½ out |
| Saturday, May 22 |
| » Defeated Giants (29-13), 2-1 | Astrodome (13-12) | 20-21 | Won 2 |
| » Starters: Rich Robertson vs Don Wilson | Second | 8½ out |
| Sunday, May 23 |
| » Lost to Giants (30-13), 7-4 | Astrodome (13-13) | 20-22 | |
| » Starters: Ron Bryant vs Tom Griffin | Third | 9½ out |
| Tuesday, May 25 |
| » Defeated Padres (13-31), 3-2 | San Diego/Jack Murphy Stadium (1-0) | 21-22 | |
| » Starters: Jack Billingham vs Clay Kirby | Second | 9½ out |
| Wednesday, May 26 |
| » Defeated Padres (13-32), 2-1 | San Diego/Jack Murphy Stadium (2-0) | 22-22 | Won 2 |
| » Starters: Wade Blasingame vs Al Santorini | Second | 9 out |
| » Defeated Padres (13-33), 8-0 | San Diego/Jack Murphy Stadium (3-0) | 23-22 | Won 3 |
| » Starters: Larry Dierker vs Al Santorini | Second | 9 out |
| Friday, May 28 |
| » Lost to Reds (19-27), 1-0 | Riverfront Stadium (0-1) | 23-23 | |
| » Starters: Don Wilson vs Don Gullett | Second | 9½ out |
| Saturday, May 29 |
| » Defeated Reds (19-28), 2-1 | Riverfront Stadium (1-1) | 24-23 | |
| » Starters: Ken Forsch vs Gary Nolan | Second | 9½ out |
| Sunday, May 30 |
| » Lost to Reds (20-28), 2-1 | Riverfront Stadium (1-2) | 24-24 | |
| » Starters: Jack Billingham vs Ross Grimsley | Third | 11 out |
| Monday, May 31 |
| » Defeated Reds (20-29), 4-1 | Riverfront Stadium (2-2) | 25-24 | |
| » Starters: Larry Dierker vs Tony Cloninger | Third | 11 out |
| Tuesday, June 1 |
| » Defeated Braves (22-29), 7-6 | Atlanta-Fulton County Stadium (1-0) | 26-24 | Won 2 |
| » Starters: Wade Blasingame vs Tom Kelley | Second | 10 out |
| Wednesday, June 2 |
| » Lost to Braves (23-29), 3-1 | Atlanta-Fulton County Stadium (1-1) | 26-25 | |
| » Starters: Don Wilson vs Ron Reed | Third | 10 out |
| Thursday, June 3 |
| » Lost to Braves (24-29), 5-2 | Atlanta-Fulton County Stadium (1-2) | 26-26 | Lost 2 |
| » Starters: Ken Forsch vs Jim Nash | Third | 10½ out |
| Future Astro Carl Everett is born in Tampa, FL. |
| Friday, June 4 |
| » Lost to Pirates (32-20), 3-2 | Three Rivers Stadium (0-1) | 26-27 | Lost 3 |
| » Starters: Jack Billingham vs Bob Moose | Third | 10½ out |
| Saturday, June 5 |
| » Defeated Pirates (32-21), 4-1 | Three Rivers Stadium (1-1) | 27-27 | |
| » Starters: Larry Dierker vs Steve Blass | Third | 9½ out |
| Sunday, June 6 |
| » Lost to Pirates (33-21), 9-8 | Three Rivers Stadium (1-2) | 27-28 | |
| » Starters: Wade Blasingame vs Dock Ellis | Third | 10 out |
| Monday, June 7 |
| Future Astro Roberto Petagine is born in Nueva Esparta, Venezuela. |
| Tuesday, June 8 |
| » Defeated Reds (22-34), 2-0 | Astrodome (14-13) | 28-28 | |
| » Starters: Gary Nolan vs Don Wilson | Third | 9 out |
| Wednesday, June 9 |
| » Lost to Reds (23-34), 2-1 | Astrodome (14-14) | 28-29 | |
| » Starters: Ross Grimsley vs Jack Billingham | Third | 9 out |
| Thursday, June 10 |
| » Lost to Braves (28-32), 2-1 | Astrodome (14-15) | 28-30 | Lost 2 |
| » Starters: Tom Kelley vs Larry Dierker | Third | 9 out |
| Friday, June 11 |
| » Defeated Braves (28-33), 5-4 | Astrodome (15-15) | 29-30 | |
| » Starters: Jim Nash vs Wade Blasingame | Third | 9 out |
| Saturday, June 12 |
| » Defeated Braves (28-34), 3-2 | Astrodome (16-15) | 30-30 | Won 2 |
| » Starters: Ron Reed vs Ken Forsch | Third | 9 out |
| Sunday, June 13 |
| » Lost to Braves (29-34), 9-0 | Astrodome (16-16) | 30-31 | |
| » Starters: Pat Jarvis vs Don Wilson | Third | 9 out |
| Monday, June 14 |
| » Defeated Pirates (38-24), 5-4 | Astrodome (17-16) | 31-31 | |
| » Starters: Bob Moose vs Jack Billingham | Third | 8 out |
| Tuesday, June 15 |
| » Lost to Pirates (39-24), 3-0 | Astrodome (17-17) | 31-32 | |
| » Starters: Steve Blass vs Larry Dierker | Third | 9 out |
| Wednesday, June 16 |
| » Lost to Pirates (40-24), 6-4 | Astrodome (17-18) | 31-33 | Lost 2 |
| » Starters: Dock Ellis vs Wade Blasingame | Third | 9 out |
| Friday, June 18 |
| » Lost to Dodgers (36-29), 5-4 | Dodger Stadium (2-2) | 31-34 | Lost 3 |
| » Starters: Don Wilson vs Claude Osteen | Third | 10½ out |
| Saturday, June 19 |
| » Lost to Dodgers (37-29), 4-0 | Dodger Stadium (2-3) | 31-35 | Lost 4 |
| » Starters: Jack Billingham vs Don Sutton | Third | 11½ out |
| Sunday, June 20 |
| » Defeated Dodgers (37-30), 9-7 | Dodger Stadium (3-3) | 32-35 | |
| » Starters: Larry Dierker vs Al Downing | Third | 12 out |
| Tuesday, June 22 |
| » Defeated Padres (23-48), 4-2 | San Diego/Jack Murphy Stadium (4-0) | 33-35 | Won 2 |
| » Starters: Ken Forsch vs Steve Arlin | Third | 12 out |
| Wednesday, June 23 |
| » Lost to Padres (24-48), 3-2 | San Diego/Jack Murphy Stadium (4-1) | 33-36 | |
| » Starters: Don Wilson vs Clay Kirby | Third | 13½ out |
| » Lost to Padres (25-48), 4-3 | San Diego/Jack Murphy Stadium (4-2) | 33-37 | Lost 2 |
| » Starters: Wade Blasingame vs Tom Phoebus | Third | 13½ out |
| Friday, June 25 |
| » Defeated Giants (48-26), 5-4 | Astrodome (18-18) | 34-37 | |
| » Starters: Gaylord Perry vs Jack Billingham | Third | 12½ out |
| Saturday, June 26 |
| » Lost to Giants (49-26), 3-1 | Astrodome (18-19) | 34-38 | |
| » Starters: Ron Bryant vs Larry Dierker | Third | 13½ out |
| Sunday, June 27 |
| » Defeated Giants (49-27), 5-2 | Astrodome (19-19) | 35-38 | |
| » Starters: Steve Stone vs Ken Forsch | Third | 12½ out |
| Monday, June 28 |
| » Defeated Braves (36-44), 6-5 | Astrodome (20-19) | 36-38 | Won 2 |
| » Starters: Steve Barber vs Don Wilson | Third | 11 out |
| » Defeated Braves (36-45), 6-4 | Astrodome (21-19) | 37-38 | Won 3 |
| » Starters: Jim Nash vs Wade Blasingame | Third | 11 out |
| Tuesday, June 29 |
| » Lost to Braves (37-45), 5-4 | Astrodome (21-20) | 37-39 | |
| » Starters: Phil Niekro vs Jack Billingham | Third | 12 out |
| Friday, July 2 |
| » Defeated Reds (37-45), 3-2 | Astrodome (22-20) | 38-39 | |
| » Starters: Gary Nolan vs Larry Dierker | Third | 11 out |
| Saturday, July 3 |
| » Defeated Reds (37-46), 4-3 | Astrodome (23-20) | 39-39 | Won 2 |
| » Starters: Don Gullett vs Don Wilson | Third | 11 out |
| Sunday, July 4 |
| » Defeated Reds (37-47), 6-1 | Astrodome (24-20) | 40-39 | Won 3 |
| » Starters: Ross Grimsley vs Wade Blasingame | Third | 10 out |
| Monday, July 5 |
| » Defeated Reds (37-48), 4-3 | Astrodome (25-20) | 41-39 | Won 4 |
| » Starters: Wayne Simpson vs Ken Forsch | Third | 9 out |
| Tuesday, July 6 |
| » Defeated Giants (52-33), 5-2 | Candlestick Park (1-2) | 42-39 | Won 5 |
| » Starters: Jack Billingham vs Ron Bryant | Third | 8 out |
| Wednesday, July 7 |
| » Defeated Giants (52-34), 18-4 | Candlestick Park (2-2) | 43-39 | Won 6 |
| » Starters: Larry Dierker vs Steve Stone | Third | 7 out |
| Thursday, July 8 |
| » Lost to Giants (53-34), 4-2 | Candlestick Park (2-3) | 43-40 | |
| » Starters: Don Wilson vs John Cumberland | Third | 8 out |
| Friday, July 9 |
| » Lost to Cardinals (43-42), 5-2 | Busch Stadium II (1-2) | 43-41 | Lost 2 |
| » Starters: Ken Forsch vs Steve Carlton | Third | 9½ out |
| » Lost to Cardinals (44-42), 9-5 | Busch Stadium II (1-3) | 43-42 | Lost 3 |
| » Starters: Wade Blasingame vs Jerry Reuss | Third | 9½ out |
| Saturday, July 10 |
| » Lost to Cardinals (45-42), 6-5 | Busch Stadium II (1-4) | 43-43 | Lost 4 |
| » Starters: Jack Billingham vs Reggie Cleveland | Third | 10½ out |
| Sunday, July 11 |
| » Lost to Cardinals (46-42), 7-3 | Busch Stadium II (1-5) | 43-44 | Lost 5 |
| » Starters: Jim Ray vs Bob Gibson | Third | 10½ out |
| Thursday, July 15 |
| » Lost to Mets (47-40), 9-4 | Astrodome (25-21) | 43-45 | Lost 6 |
| » Starters: Gary Gentry vs Ken Forsch | Third | 10½ out |
| Friday, July 16 |
| » Defeated Mets (47-41), 9-4 | Astrodome (26-21) | 44-45 | |
| » Starters: Nolan Ryan vs Jack Billingham | Third | 10½ out |
| Saturday, July 17 |
| » Defeated Mets (47-42), 2-1 | Astrodome (27-21) | 45-45 | Won 2 |
| » Starters: Tom Seaver vs Larry Dierker | Third | 9½ out |
| Sunday, July 18 |
| » Lost to Phillies (41-52), 1-0 | Astrodome (27-22) | 45-46 | |
| » Starters: Ken Reynolds vs Don Wilson | Third | 9½ out |
| » Defeated Phillies (41-53), 10-7 | Astrodome (28-22) | 46-46 | |
| » Starters: Jim Bunning vs Wade Blasingame | Third | 9½ out |
| Monday, July 19 |
| » Defeated Phillies (41-54), 3-2 | Astrodome (29-22) | 47-46 | Won 2 |
| » Starters: Rick Wise vs Bill Greif | Third | 9½ out |
| » Major-league debuts: Bill Greif (Astros) |
| Tuesday, July 20 |
| » Lost to Expos (38-57), 4-3 | Astrodome (29-23) | 47-47 | |
| » Starters: Bill Stoneman vs Ken Forsch | Third | 9½ out |
| Wednesday, July 21 |
| » Lost to Expos (39-57), 5-3 | Astrodome (29-24) | 47-48 | Lost 2 |
| » Starters: Steve Renko vs Jack Billingham | Third | 10½ out |
| Thursday, July 22 |
| » Defeated Expos (39-58), 8-2 | Astrodome (30-24) | 48-48 | |
| » Starters: Ernie McAnally vs Wade Blasingame | Third | 10½ out |
| Friday, July 23 |
| » Defeated Mets (49-46), 5-1 | Shea Stadium (2-2) | 49-48 | Won 2 |
| » Starters: Don Wilson vs Nolan Ryan | Fourth | 9½ out |
| Saturday, July 24 |
| » Lost to Mets (50-46), 9-3 | Shea Stadium (2-3) | 49-49 | |
| » Starters: Bill Greif vs Jon Matlack | Third | 10½ out |
| » Major-league debuts: Ray Busse (Astros) |
| Sunday, July 25 |
| » Lost to Mets (51-46), 7-6 | Shea Stadium (2-4) | 49-50 | Lost 2 |
| » Starters: Ken Forsch vs Gary Gentry | Fourth | 11 out |
| Future Astro Billy Wagner is born in Tannersville, VA. |
| Monday, July 26 |
| » Defeated Phillies (44-58), 7-4 | Veteran's Stadium (2-1) | 50-50 | |
| » Starters: Jack Billingham vs Barry Lersch | Fourth | 10½ out |
| Tuesday, July 27 |
| » Lost to Phillies (45-58), 8-3 | Veteran's Stadium (2-2) | 50-51 | |
| » Starters: Larry Dierker vs Woodie Fryman | Fourth | 10 out |
| » Defeated Phillies (45-59), 5-1 | Veteran's Stadium (3-2) | 51-51 | |
| » Starters: Wade Blasingame vs Ken Reynolds | Fourth | 10 out |
| Wednesday, July 28 |
| » Defeated Phillies (45-60), 6-3 | Veteran's Stadium (4-2) | 52-51 | Won 2 |
| » Starters: Don Wilson vs Rick Wise | Fourth | 10 out |
| Friday, July 30 |
| » Lost to Expos (42-63), 7-4 | Parc Jarry (1-2) | 52-52 | |
| » Starters: Ken Forsch vs John Strohmayer | Fourth | 10 out |
| » Defeated Expos (42-64), 6-5 | Parc Jarry (2-2) | 53-52 | |
| » Starters: Bill Greif vs Bill Stoneman | Fourth | 10 out |
| Saturday, July 31 |
| » Lost to Expos (43-64), 6-4 | Parc Jarry (2-3) | 53-53 | |
| » Starters: Jack Billingham vs Steve Renko | Fourth | 11 out |
| Sunday, August 1 |
| » Defeated Expos (43-65), 8-1 | Parc Jarry (3-3) | 54-53 | |
| » Starters: Wade Blasingame vs Ernie McAnally | Fourth | 11½ out |
| Monday, August 2 |
| » Defeated Cubs (57-50), 2-1 | Astrodome (31-24) | 55-53 | Won 2 |
| » Starters: Fergie Jenkins vs Don Wilson | Fourth | 10½ out |
| Tuesday, August 3 |
| » Lost to Cubs (58-50), 5-0 | Astrodome (31-25) | 55-54 | |
| » Starters: Bill Hands vs Larry Dierker | Third | 10½ out |
| Wednesday, August 4 |
| » Defeated Dodgers (59-52), 2-0 | Astrodome (32-25) | 56-54 | |
| » Starters: Al Downing vs Ken Forsch | Fourth | 9½ out |
| Thursday, August 5 |
| » Lost to Dodgers (60-52), 3-0 | Astrodome (32-26) | 56-55 | |
| » Starters: Bill Singer vs Jack Billingham | Fourth | 9½ out |
| Friday, August 6 |
| » Lost to Padres (41-74), 4-3 | Astrodome (32-27) | 56-56 | Lost 2 |
| » Starters: Dave Roberts vs Wade Blasingame | Fourth | 9½ out |
| Saturday, August 7 |
| » Defeated Padres (41-75), 5-3 | Astrodome (33-27) | 57-56 | |
| » Starters: Steve Arlin vs Don Wilson | Fourth | 8½ out |
| Sunday, August 8 |
| » Lost to Padres (42-75), 3-2 | Astrodome (33-28) | 57-57 | |
| » Starters: Fred Norman vs Larry Dierker | Fourth | 9 out |
| Tuesday, August 10 |
| » Defeated Reds (54-64), 3-2 | Riverfront Stadium (3-2) | 58-57 | |
| » Starters: Ken Forsch vs Wayne Simpson | Fourth | 9 out |
| Wednesday, August 11 |
| » Lost to Reds (55-64), 5-1 | Riverfront Stadium (3-3) | 58-58 | |
| » Starters: Jack Billingham vs Gary Nolan | Fourth | 9 out |
| Thursday, August 12 |
| » Lost to Braves (63-58), 10-5 | Atlanta-Fulton County Stadium (1-3) | 58-59 | Lost 2 |
| » Starters: Wade Blasingame vs Ron Reed | Fourth | 9½ out |
| Friday, August 13 |
| » Defeated Braves (63-59), 8-2 | Atlanta-Fulton County Stadium (2-3) | 59-59 | |
| » Starters: Don Wilson vs Phil Niekro | Fourth | 9½ out |
| Saturday, August 14 |
| » Lost to Braves (64-59), 7-0 | Atlanta-Fulton County Stadium (2-4) | 59-60 | |
| » Starters: Ron Cook vs Pat Jarvis | Fourth | 10½ out |
| Future Astro Mark Loretta is born in Santa Monica, CA. |
| Sunday, August 15 |
| » Defeated Braves (64-60), 5-4 | Atlanta-Fulton County Stadium (3-4) | 60-60 | |
| » Starters: Ken Forsch vs George Stone | Fourth | 10½ out |
| Monday, August 16 |
| » Lost to Pirates (72-50), 8-3 | Three Rivers Stadium (1-3) | 60-61 | |
| » Starters: Jack Billingham vs Dock Ellis | Fourth | 11 out |
| Tuesday, August 17 |
| » Defeated Pirates (72-51), 6-5 | Three Rivers Stadium (2-3) | 61-61 | |
| » Starters: Wade Blasingame vs Luke Walker | Fourth | 11 out |
| Wednesday, August 18 |
| » Lost to Pirates (73-51), 3-2 | Three Rivers Stadium (2-4) | 61-62 | |
| » Starters: Don Wilson vs Steve Blass | Fourth | 12 out |
| Friday, August 20 |
| » Lost to Cubs (67-55), 3-2 | Wrigley Field (1-2) | 61-63 | Lost 2 |
| » Starters: Ron Cook vs Fergie Jenkins | Fourth | 12½ out |
| » Lost to Cubs (68-55), 5-4 | Wrigley Field (1-3) | 61-64 | Lost 3 |
| » Starters: Ken Forsch vs Ken Holtzman | Fourth | 12½ out |
| » Major-league debuts: Gene Hiser (Cubs) |
| Saturday, August 21 |
| » Defeated Cubs (68-56), 3-0 | Wrigley Field (2-3) | 62-64 | |
| » Starters: Jack Billingham vs Bill Hands | Fourth | 11½ out |
| Sunday, August 22 |
| » Defeated Cubs (68-57), 4-3 | Wrigley Field (3-3) | 63-64 | Won 2 |
| » Starters: Wade Blasingame vs Milt Pappas | Fourth | 10½ out |
| Monday, August 23 |
| » Lost to Cardinals (70-59), 3-2 | Astrodome (33-29) | 63-65 | |
| » Starters: Bob Gibson vs Don Wilson | Fourth | 11½ out |
| Tuesday, August 24 |
| » Lost to Cardinals (71-59), 2-1 | Astrodome (33-30) | 63-66 | Lost 2 |
| » Starters: Reggie Cleveland vs Ken Forsch | Fifth | 12½ out |
| Wednesday, August 25 |
| » Lost to Cardinals (72-59), 4-1 | Astrodome (33-31) | 63-67 | Lost 3 |
| » Starters: Steve Carlton vs Ron Cook | Fifth | 12½ out |
| Friday, August 27 |
| » Lost to Pirates (78-55), 7-3 | Astrodome (33-32) | 63-68 | Lost 4 |
| » Starters: Dock Ellis vs Jack Billingham | Fifth | 13 out |
| Saturday, August 28 |
| » Defeated Pirates (78-56), 4-0 | Astrodome (34-32) | 64-68 | |
| » Starters: Steve Blass vs Don Wilson | Fifth | 12½ out |
| Sunday, August 29 |
| » Lost to Pirates (79-56), 5-2 | Astrodome (34-33) | 64-69 | |
| » Starters: Bob Johnson vs Wade Blasingame | Fifth | 13½ out |
| Monday, August 30 |
| » Lost to Dodgers (70-64), 3-2 | Astrodome (34-34) | 64-70 | Lost 2 |
| » Starters: Al Downing vs Ken Forsch | Fifth | 14 out |
| Tuesday, August 31 |
| » Lost to Dodgers (71-64), 6-1 | Astrodome (34-35) | 64-71 | Lost 3 |
| » Starters: Doyle Alexander vs Ron Cook | Fifth | 15 out |
| Wednesday, September 1 |
| » Lost to Dodgers (72-64), 9-2 | Astrodome (34-36) | 64-72 | Lost 4 |
| » Starters: Don Sutton vs Jack Billingham | Fifth | 16 out |
| Thursday, September 2 |
| » Defeated Dodgers (72-65), 9-3 | Astrodome (35-36) | 65-72 | |
| » Starters: Claude Osteen vs Don Wilson | Fifth | 15½ out |
| Friday, September 3 |
| » Lost to Giants (81-56), 16-6 | Candlestick Park (2-4) | 65-73 | |
| » Starters: Wade Blasingame vs Juan Marichal | Fifth | 16½ out |
| Saturday, September 4 |
| » Lost to Giants (82-56), 1-0 | Candlestick Park (2-5) | 65-74 | Lost 2 |
| » Starters: Ken Forsch vs Don Carrithers | Fifth | 17½ out |
| Sunday, September 5 |
| » Defeated Giants (82-57), 1-0 | Candlestick Park (3-5) | 66-74 | |
| » Starters: Jack Billingham vs Gaylord Perry | Fifth | 15½ out |
| » Defeated Giants (82-58), 5-3 | Candlestick Park (4-5) | 67-74 | Won 2 |
| » Starters: J.R. Richard vs Jim Willoughby | Fifth | 15½ out |
| » Major-league debuts: Dave Rader and Jim Willoughby (Giants) J.R. Richard (Astros) |
| Monday, September 6 |
| » Defeated Braves (72-71), 6-4 | Atlanta-Fulton County Stadium (4-4) | 68-74 | Won 3 |
| » Starters: Scipio Spinks vs George Stone | Fifth | 14½ out |
| Tuesday, September 7 |
| » Defeated Braves (72-72), 5-1 | Atlanta-Fulton County Stadium (5-4) | 69-74 | Won 4 |
| » Starters: Don Wilson vs Ron Reed | Fifth | 13½ out |
| Friday, September 10 |
| » Defeated Reds (71-75), 1-0 | Riverfront Stadium (4-3) | 70-74 | Won 5 |
| » Starters: Jack Billingham vs Jim McGlothlin | Fourth | 12 out |
| Saturday, September 11 |
| » Defeated Reds (71-76), 5-2 | Riverfront Stadium (5-3) | 71-74 | Won 6 |
| » Starters: J.R. Richard vs Ross Grimsley | Fourth | 11 out |
| Sunday, September 12 |
| » Defeated Reds (71-77), 4-2 | Riverfront Stadium (6-3) | 72-74 | Won 7 |
| » Starters: Don Wilson vs Wayne Simpson | Fourth | 11 out |
| Monday, September 13 |
| » Defeated Padres (54-93), 3-2 | Astrodome (36-36) | 73-74 | Won 8 |
| » Starters: Clay Kirby vs Ken Forsch | Fourth | 10 out |
| Tuesday, September 14 |
| » Lost to Padres (55-93), 5-2 | Astrodome (36-37) | 73-75 | |
| » Starters: Ed Acosta vs Wade Blasingame | Fourth | 10 out |
| » Major-league debuts: Derrel Thomas (Astros) |
| Wednesday, September 15 |
| » Lost to Braves (76-74), 4-2 | Astrodome (36-38) | 73-76 | Lost 2 |
| » Starters: Phil Niekro vs Jack Billingham | Fourth | 10 out |
| » Major-league debuts: Larry Yount (Astros) |
| Thursday, September 16 |
| » Lost to Braves (77-74), 4-3 | Astrodome (36-39) | 73-77 | Lost 3 |
| » Starters: Tom Kelley vs J.R. Richard | Fourth | 10 out |
| Friday, September 17 |
| » Defeated Reds (74-79), 4-1 | Astrodome (37-39) | 74-77 | |
| » Starters: Wayne Simpson vs Don Wilson | Fourth | 10 out |
| Saturday, September 18 |
| » Lost to Reds (75-79), 3-2 | Astrodome (37-40) | 74-78 | |
| » Starters: Gary Nolan vs Ken Forsch | Fourth | 10 out |
| Future Astro Chris Holt is born in Dallas, TX. |
| Sunday, September 19 |
| » Defeated Reds (75-80), 5-4 | Astrodome (38-40) | 75-78 | |
| » Starters: Jim Merritt vs Scipio Spinks | Fourth | 10 out |
| Tuesday, September 21 |
| » Defeated Giants (85-69), 3-1 | Astrodome (39-40) | 76-78 | Won 2 |
| » Starters: John Cumberland vs Jack Billingham | Fourth | 9 out |
| Wednesday, September 22 |
| » Lost to Giants (86-69), 3-1 | Astrodome (39-41) | 76-79 | |
| » Starters: Juan Marichal vs J.R. Richard | Fourth | 10 out |
| Thursday, September 23 |
| » Lost to Giants (87-69), 2-1 | Astrodome (39-42) | 76-80 | Lost 2 |
| » Starters: Gaylord Perry vs Don Wilson | Fifth | 11 out |
| Friday, September 24 |
| » Defeated Padres (59-97), 2-1 | San Diego/Jack Murphy Stadium (5-2) | 77-80 | |
| » Starters: Ken Forsch vs Clay Kirby | Fifth | 10½ out |
| » Lost to Padres (60-97), 5-4 | San Diego/Jack Murphy Stadium (5-3) | 77-81 | |
| » Starters: Scipio Spinks vs Dave Roberts | Fifth | 10½ out |
| Saturday, September 25 |
| » Defeated Padres (60-98), 5-1 | San Diego/Jack Murphy Stadium (6-3) | 78-81 | |
| » Starters: Jack Billingham vs Steve Arlin | Fifth | 9½ out |
| Tuesday, September 28 |
| » Lost to Dodgers (88-72), 2-1 | Dodger Stadium (3-4) | 78-82 | |
| » Starters: Don Wilson vs Bill Singer | Fifth | 11 out |
| Wednesday, September 29 |
| » Defeated Dodgers (88-73), 11-0 | Dodger Stadium (4-4) | 79-82 | |
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