| Friday, January 16 |
| Future Astro Ron Villone is born in Englewood, NJ. |
| Wednesday, January 21 |
| Future Astro Jeff McCurry is born in Tokyo, Japan. |
| Monday, April 6 |
| » Major-league debuts: Dick Such (Senators) |
| Tuesday, April 7 |
| » Defeated Giants (0-1), 8-5 | Candlestick Park (1-0) | 1-0 | |
| » Starters: Larry Dierker vs Gaylord Perry | Second | ½ out |
| » Major-league debuts: Alan Gallagher (Giants) |
| Wednesday, April 8 |
| » Lost to Giants (1-1), 5-4 | Candlestick Park (1-1) | 1-1 | |
| » Starters: Denny Lemaster vs Mike McCormick | Second | 1½ out |
| Thursday, April 9 |
| » Lost to Giants (2-1), 7-4 | Candlestick Park (1-2) | 1-2 | Lost 2 |
| » Starters: Jim Ray vs Frank Reberger | Third | 2½ out |
| Friday, April 10 |
| » Lost to Braves (3-1), 5-0 | Astrodome (0-1) | 1-3 | Lost 3 |
| » Starters: George Stone vs Tom Griffin | Fourth | 2½ out |
| Saturday, April 11 |
| » Defeated Braves (3-2), 8-7 | Astrodome (1-1) | 2-3 | |
| » Starters: Milt Pappas vs Jim Bouton | Fourth | 2 out |
| Future Astro Sean Bergman is born in Joliet, IL. |
| Sunday, April 12 |
| » Defeated Braves (3-3), 8-3 | Astrodome (2-1) | 3-3 | Won 2 |
| » Starters: Phil Niekro vs Larry Dierker | Third | 2 out |
| Monday, April 13 |
| » Lost to Dodgers (2-5), 2-0 | Astrodome (2-2) | 3-4 | |
| » Starters: Don Sutton vs Denny Lemaster | Fourth | 2 out |
| Tuesday, April 14 |
| » Lost to Dodgers (3-5), 3-2 | Astrodome (2-3) | 3-5 | Lost 2 |
| » Starters: Alan Foster vs Jim Ray | Fourth | 3 out |
| Wednesday, April 15 |
| » Defeated Giants (5-5), 7-6 | Astrodome (3-3) | 4-5 | |
| » Starters: Gaylord Perry vs Tom Griffin | Fourth | 3 out |
| Thursday, April 16 |
| » Lost to Giants (6-5), 11-9 | Astrodome (3-4) | 4-6 | |
| » Starters: Mike McCormick vs Jim Bouton | Fourth | 4 out |
| Friday, April 17 |
| » Defeated Padres (5-6), 4-1 | Astrodome (4-4) | 5-6 | |
| » Starters: Dave Roberts vs Larry Dierker | Fourth | 4 out |
| Saturday, April 18 |
| » Defeated Padres (5-7), 4-3 | Astrodome (5-4) | 6-6 | Won 2 |
| » Starters: Danny Coombs vs Denny Lemaster | Third | 3 out |
| Sunday, April 19 |
| » Defeated Padres (5-8), 5-1 | Astrodome (6-4) | 7-6 | Won 3 |
| » Starters: Al Santorini vs Tom Griffin | Second | 3 out |
| Monday, April 20 |
| » Lost to Pirates (6-4), 3-1 | Forbes Field (0-1) | 7-7 | |
| » Starters: Jim Bouton vs Dock Ellis | Second | 4 out |
| Tuesday, April 21 |
| » Lost to Pirates (7-4), 9-8 | Forbes Field (0-2) | 7-8 | Lost 2 |
| » Starters: Larry Dierker vs Bob Veale | Third | 5 out |
| Wednesday, April 22 |
| » Lost to Pirates (8-4), 6-1 | Forbes Field (0-3) | 7-9 | Lost 3 |
| » Starters: Denny Lemaster vs Steve Blass | Fourth | 5½ out |
| Friday, April 24 |
| » Lost to Cubs (9-3), 6-3 | Wrigley Field (0-1) | 7-10 | Lost 4 |
| » Starters: Tom Griffin vs Ken Holtzman | Fourth | 5½ out |
| Saturday, April 25 |
| » Lost to Cubs (10-3), 11-5 | Wrigley Field (0-2) | 7-11 | Lost 5 |
| » Starters: Jim Bouton vs Bill Hands | Fourth | 6½ out |
| Sunday, April 26 |
| » Lost to Cubs (11-3), 6-3 | Wrigley Field (0-3) | 7-12 | Lost 6 |
| » Starters: Larry Dierker vs Fergie Jenkins | Fifth | 6½ out |
| Tuesday, April 28 |
| » Lost to Reds (15-6), 4-2 | Crosley Field (0-1) | 7-13 | Lost 7 |
| » Starters: Denny Lemaster vs Gary Nolan | Fifth | 7½ out |
| Wednesday, April 29 |
| » Lost to Reds (16-6), 5-3 | Crosley Field (0-2) | 7-14 | Lost 8 |
| » Starters: Tom Griffin vs Jim Merritt | Fifth | 8½ out |
| Future Astro J.R. Phillips is born in West Covina, CA. |
| Friday, May 1 |
| » Defeated Cardinals (9-8), 9-3 | Busch Stadium II (1-0) | 8-14 | |
| » Starters: Larry Dierker vs Steve Carlton | Fifth | 8½ out |
| Saturday, May 2 |
| » Defeated Cardinals (9-9), 5-3 | Busch Stadium II (2-0) | 9-14 | Won 2 |
| » Starters: Don Wilson vs Bob Gibson | Fifth | 8½ out |
| Sunday, May 3 |
| » Lost to Cardinals (10-9), 7-4 | Busch Stadium II (2-1) | 9-15 | |
| » Starters: Tom Griffin vs Nelson Briles | Fourth | 9 out |
| » Defeated Cardinals (10-10), 8-1 | Busch Stadium II (3-1) | 10-15 | |
| » Starters: Denny Lemaster vs George Culver | Fourth | 9 out |
| Monday, May 4 |
| » Defeated Cubs (13-8), 7-2 | Astrodome (7-4) | 11-15 | Won 2 |
| » Starters: Bill Hands vs Jim Bouton | Fifth | 9 out |
| Tuesday, May 5 |
| » Defeated Cubs (13-9), 3-1 | Astrodome (8-4) | 12-15 | Won 3 |
| » Starters: Fergie Jenkins vs Larry Dierker | Fifth | 9 out |
| Thursday, May 7 |
| » Lost to Pirates (12-14), 9-5 | Astrodome (8-5) | 12-16 | |
| » Starters: Bob Veale vs Don Wilson | Fifth | 10 out |
| Friday, May 8 |
| » Defeated Pirates (12-15), 7-5 | Astrodome (9-5) | 13-16 | |
| » Starters: Steve Blass vs Denny Lemaster | Fifth | 9 out |
| Saturday, May 9 |
| » Lost to Pirates (13-15), 6-3 | Astrodome (9-6) | 13-17 | |
| » Starters: Dock Ellis vs Tom Griffin | Fifth | 9 out |
| Sunday, May 10 |
| » Defeated Pirates (13-16), 9-2 | Astrodome (10-6) | 14-17 | |
| » Starters: Bob Moose vs Larry Dierker | Fourth | 9 out |
| Tuesday, May 12 |
| » Defeated Dodgers (17-13), 8-3 | Dodger Stadium (1-0) | 15-17 | Won 2 |
| » Starters: Don Wilson vs Alan Foster | Fifth | 8½ out |
| Wednesday, May 13 |
| » Defeated Dodgers (17-14), 6-5 | Dodger Stadium (2-0) | 16-17 | Won 3 |
| » Starters: Denny Lemaster vs Claude Osteen | Fifth | 8 out |
| Thursday, May 14 |
| » Defeated Padres (15-21), 3-1 | San Diego/Jack Murphy Stadium (1-0) | 17-17 | Won 4 |
| » Starters: Larry Dierker vs Clay Kirby | Fourth | 7½ out |
| Friday, May 15 |
| » Lost to Padres (16-21), 10-8 | San Diego/Jack Murphy Stadium (1-1) | 17-18 | |
| » Starters: Scipio Spinks vs Dave Roberts | Fourth | 7½ out |
| Saturday, May 16 |
| » Defeated Padres (16-22), 9-7 | San Diego/Jack Murphy Stadium (2-1) | 18-18 | |
| » Starters: Don Wilson vs Pat Dobson | Fourth | 7½ out |
| Sunday, May 17 |
| » Lost to Padres (17-22), 5-3 | San Diego/Jack Murphy Stadium (2-2) | 18-19 | |
| » Starters: Denny Lemaster vs Mike Corkins | Fourth | 9 out |
| Monday, May 18 |
| » Defeated Cardinals (16-17), 6-0 | Astrodome (11-6) | 19-19 | |
| » Starters: Bob Gibson vs Larry Dierker | Fourth | 8 out |
| Tuesday, May 19 |
| » Lost to Cardinals (17-17), 12-3 | Astrodome (11-7) | 19-20 | |
| » Starters: Santiago Guzman vs Scipio Spinks | Fourth | 9 out |
| Wednesday, May 20 |
| » Lost to Cardinals (18-17), 3-2 | Astrodome (11-8) | 19-21 | Lost 2 |
| » Starters: Mike Torrez vs Tom Griffin | Fourth | 9½ out |
| Thursday, May 21 |
| » Lost to Reds (29-11), 3-0 | Astrodome (11-9) | 19-22 | Lost 3 |
| » Starters: Jim McGlothlin vs Denny Lemaster | Fourth | 10½ out |
| Future Astro Tom Martin is born in Charleston, SC. |
| Friday, May 22 |
| » Lost to Reds (30-11), 5-2 | Astrodome (11-10) | 19-23 | Lost 4 |
| » Starters: Jim Merritt vs Larry Dierker | Fifth | 11½ out |
| Saturday, May 23 |
| » Lost to Reds (31-11), 14-3 | Astrodome (11-11) | 19-24 | Lost 5 |
| » Starters: Wayne Simpson vs Don Wilson | Fifth | 12½ out |
| Future Astro Ricky Gutierrez is born in Miami, FL. |
| Sunday, May 24 |
| » Defeated Reds (31-12), 10-7 | Astrodome (12-11) | 20-24 | |
| » Starters: Gary Nolan vs Jim Bouton | Fifth | 11½ out |
| Tuesday, May 26 |
| » Lost to Braves (24-18), 5-3 | Atlanta-Fulton County Stadium (0-1) | 20-25 | |
| » Starters: Larry Dierker vs Jim Nash | Fifth | 11½ out |
| Wednesday, May 27 |
| » Lost to Braves (25-18), 8-1 | Atlanta-Fulton County Stadium (0-2) | 20-26 | Lost 2 |
| » Starters: Denny Lemaster vs Phil Niekro | Fifth | 12½ out |
| Friday, May 29 |
| » Defeated Mets (22-23), 5-0 | Shea Stadium (1-0) | 21-26 | |
| » Starters: Tom Griffin vs Tom Seaver | Fifth | 12½ out |
| Saturday, May 30 |
| » Lost to Mets (23-23), 4-3 | Shea Stadium (1-1) | 21-27 | |
| » Starters: Larry Dierker vs Nolan Ryan | Fifth | 13½ out |
| Sunday, May 31 |
| » Lost to Mets (24-23), 14-4 | Shea Stadium (1-2) | 21-28 | Lost 2 |
| » Starters: Denny Lemaster vs Ray Sadecki | Fifth | 15 out |
| » Lost to Mets (25-23), 4-3 | Shea Stadium (1-3) | 21-29 | Lost 3 |
| » Starters: Don Wilson vs Jim McAndrew | Fifth | 15 out |
| Tuesday, June 2 |
| » Defeated Expos (16-31), 6-4 | Astrodome (13-11) | 22-29 | |
| » Starters: Carl Morton vs Ron Cook | Fifth | 15 out |
| Wednesday, June 3 |
| » Defeated Expos (16-32), 5-0 | Astrodome (14-11) | 23-29 | Won 2 |
| » Starters: Balor Moore vs Jack Billingham | Fifth | 14 out |
| Thursday, June 4 |
| » Defeated Expos (16-33), 8-0 | Astrodome (15-11) | 24-29 | Won 3 |
| » Starters: Dan McGinn vs Tom Griffin | Fifth | 13½ out |
| Friday, June 5 |
| » Defeated Phillies (21-29), 8-7 | Astrodome (16-11) | 25-29 | Won 4 |
| » Starters: Chris Short vs Denny Lemaster | Fourth | 13½ out |
| Saturday, June 6 |
| » Lost to Phillies (22-29), 7-3 | Astrodome (16-12) | 25-30 | |
| » Starters: Rick Wise vs Don Wilson | Fifth | 14½ out |
| Sunday, June 7 |
| » Lost to Phillies (23-29), 10-3 | Astrodome (16-13) | 25-31 | Lost 2 |
| » Starters: Woodie Fryman vs Larry Dierker | Fifth | 15½ out |
| Monday, June 8 |
| » Lost to Mets (26-28), 2-0 | Astrodome (16-14) | 25-32 | Lost 3 |
| » Starters: Jim McAndrew vs Jack Billingham | Fifth | 16 out |
| Tuesday, June 9 |
| » Lost to Mets (27-28), 2-1 | Astrodome (16-15) | 25-33 | Lost 4 |
| » Starters: Tom Seaver vs Tom Griffin | Fifth | 17 out |
| Wednesday, June 10 |
| » Defeated Mets (27-29), 5-3 | Astrodome (17-15) | 26-33 | |
| » Starters: Nolan Ryan vs Denny Lemaster | Fifth | 17 out |
| » Major-league debuts: Rich Folkers (Mets) |
| Friday, June 12 |
| » Lost to Expos (21-35), 7-6 | Parc Jarry (0-1) | 26-34 | |
| » Starters: Ron Cook vs Dan McGinn | Fifth | 17½ out |
| Saturday, June 13 |
| » Defeated Expos (21-36), 5-2 | Parc Jarry (1-1) | 27-34 | |
| » Starters: Jack Billingham vs Bill Stoneman | Fifth | 16½ out |
| Sunday, June 14 |
| » Lost to Expos (22-36), 2-1 | Parc Jarry (1-2) | 27-35 | |
| » Starters: Denny Lemaster vs Steve Renko | Fifth | 17½ out |
| Tuesday, June 16 |
| » Lost to Phillies (26-33), 2-1 | Shibe Park (0-1) | 27-36 | Lost 2 |
| » Starters: Tom Griffin vs Rick Wise | Sixth | 17½ out |
| Wednesday, June 17 |
| » Lost to Phillies (27-33), 4-2 | Shibe Park (0-2) | 27-37 | Lost 3 |
| » Starters: Larry Dierker vs Woodie Fryman | Sixth | 18½ out |
| Friday, June 19 |
| » Lost to Braves (34-27), 7-6 | Atlanta-Fulton County Stadium (0-3) | 27-38 | Lost 4 |
| » Starters: Jack Billingham vs Mike McQueen | Sixth | 19 out |
| » Lost to Braves (35-27), 4-2 | Atlanta-Fulton County Stadium (0-4) | 27-39 | Lost 5 |
| » Starters: Denny Lemaster vs Pat Jarvis | Sixth | 19 out |
| Saturday, June 20 |
| » Defeated Braves (35-28), 9-6 | Atlanta-Fulton County Stadium (1-4) | 28-39 | |
| » Starters: Tom Griffin vs George Stone | Sixth | 19 out |
| » Major-league debuts: Cesar Cedeno (Astros) |
| Sunday, June 21 |
| » Lost to Braves (36-28), 6-4 | Atlanta-Fulton County Stadium (1-5) | 28-40 | |
| » Starters: Larry Dierker vs Jim Nash | Sixth | 19½ out |
| Monday, June 22 |
| » Defeated Padres (30-42), 4-1 | Astrodome (18-15) | 29-40 | |
| » Starters: Dave Roberts vs Don Wilson | Fifth | 18½ out |
| Tuesday, June 23 |
| » Defeated Padres (30-43), 2-1 | Astrodome (19-15) | 30-40 | Won 2 |
| » Starters: Danny Coombs vs Jack Billingham | Fifth | 18½ out |
| Wednesday, June 24 |
| » Defeated Padres (30-44), 5-4 | Astrodome (20-15) | 31-40 | Won 3 |
| » Starters: Al Santorini vs Denny Lemaster | Fifth | 18½ out |
| Friday, June 26 |
| » Lost to Reds (50-21), 3-2 | Astrodome (20-16) | 31-41 | |
| » Starters: Wayne Simpson vs Larry Dierker | Fifth | 19½ out |
| Saturday, June 27 |
| » Lost to Reds (51-21), 5-2 | Astrodome (20-17) | 31-42 | Lost 2 |
| » Starters: Jim Merritt vs Tom Griffin | Fifth | 20½ out |
| Sunday, June 28 |
| » Lost to Reds (52-21), 3-2 | Astrodome (20-18) | 31-43 | Lost 3 |
| » Starters: Gary Nolan vs Don Wilson | Fifth | 21½ out |
| Monday, June 29 |
| » Defeated Dodgers (43-31), 10-5 | Dodger Stadium (3-0) | 32-43 | |
| » Starters: Jack Billingham vs Bill Singer | Fifth | 21 out |
| Tuesday, June 30 |
| » Defeated Dodgers (43-32), 6-2 | Dodger Stadium (4-0) | 33-43 | Won 2 |
| » Starters: Denny Lemaster vs Joe Moeller | Fifth | 20 out |
| Wednesday, July 1 |
| » Lost to Dodgers (44-32), 6-3 | Dodger Stadium (4-1) | 33-44 | |
| » Starters: Larry Dierker vs Claude Osteen | Fifth | 21 out |
| Friday, July 3 |
| » Lost to Reds (55-22), 3-0 | Riverfront Stadium (0-1) | 33-45 | Lost 2 |
| » Starters: Don Wilson vs Gary Nolan | Fifth | 21½ out |
| » Defeated Reds (55-23), 10-4 | Riverfront Stadium (1-1) | 34-45 | |
| » Starters: Tom Griffin vs Tony Cloninger | Fifth | 21½ out |
| Saturday, July 4 |
| » Lost to Reds (56-23), 3-0 | Riverfront Stadium (1-2) | 34-46 | |
| » Starters: Jack Billingham vs Jim McGlothlin | Fifth | 22½ out |
| Sunday, July 5 |
| » Lost to Reds (57-23), 3-1 | Riverfront Stadium (1-3) | 34-47 | Lost 2 |
| » Starters: Denny Lemaster vs Wayne Simpson | Fifth | 23½ out |
| Monday, July 6 |
| » Lost to Dodgers (48-32), 10-8 | Astrodome (20-19) | 34-48 | Lost 3 |
| » Starters: Claude Osteen vs Larry Dierker | Fifth | 24½ out |
| Tuesday, July 7 |
| » Lost to Dodgers (49-32), 7-2 | Astrodome (20-20) | 34-49 | Lost 4 |
| » Starters: Joe Moeller vs Tom Griffin | Fifth | 25½ out |
| Wednesday, July 8 |
| » Lost to Dodgers (50-32), 6-5 | Astrodome (20-21) | 34-50 | Lost 5 |
| » Starters: Don Sutton vs Don Wilson | Fifth | 25½ out |
| Thursday, July 9 |
| » Defeated Dodgers (50-33), 9-5 | Astrodome (21-21) | 35-50 | |
| » Starters: Alan Foster vs Jack Billingham | Fifth | 24½ out |
| Friday, July 10 |
| » Lost to Giants (41-42), 8-5 | Astrodome (21-22) | 35-51 | |
| » Starters: Frank Reberger vs Denny Lemaster | Fifth | 25 out |
| Saturday, July 11 |
| » Defeated Giants (41-43), 5-4 | Astrodome (22-22) | 36-51 | |
| » Starters: Rich Robertson vs Larry Dierker | Fifth | 25 out |
| Sunday, July 12 |
| » Defeated Giants (41-44), 8-7 | Astrodome (23-22) | 37-51 | Won 2 |
| » Starters: Gaylord Perry vs Tom Griffin | Fifth | 25 out |
| Thursday, July 16 |
| » Defeated Cubs (43-43), 2-1 | Astrodome (24-22) | 38-51 | Won 3 |
| » Starters: Ken Holtzman vs Don Wilson | Fifth | 25 out |
| Friday, July 17 |
| » Defeated Cubs (43-44), 5-2 | Astrodome (25-22) | 39-51 | Won 4 |
| » Starters: Fergie Jenkins vs Larry Dierker | Fifth | 24 out |
| Saturday, July 18 |
| » Lost to Cubs (44-44), 7-3 | Astrodome (25-23) | 39-52 | |
| » Starters: Bill Hands vs Jack Billingham | Fifth | 25 out |
| Sunday, July 19 |
| » Lost to Cubs (45-44), 7-1 | Astrodome (25-24) | 39-53 | Lost 2 |
| » Starters: Milt Pappas vs Tom Griffin | Fifth | 25 out |
| Monday, July 20 |
| » Defeated Pirates (52-42), 5-4 | Astrodome (26-24) | 40-53 | |
| » Starters: Dock Ellis vs Denny Lemaster | Fifth | 25½ out |
| Tuesday, July 21 |
| » Defeated Pirates (52-43), 3-1 | Astrodome (27-24) | 41-53 | Won 2 |
| » Starters: Jim Nelson vs Don Wilson | Fifth | 25½ out |
| Wednesday, July 22 |
| » Defeated Cardinals (41-53), 13-9 | Busch Stadium II (4-1) | 42-53 | Won 3 |
| » Starters: Larry Dierker vs Nelson Briles | Fifth | 24½ out |
| Thursday, July 23 |
| » Defeated Cardinals (41-54), 3-2 | Busch Stadium II (5-1) | 43-53 | Won 4 |
| » Starters: Jack Billingham vs Bob Gibson | Fifth | 23½ out |
| Friday, July 24 |
| » Lost to Pirates (55-43), 11-0 | Three Rivers Stadium (0-1) | 43-54 | |
| » Starters: Tom Griffin vs Dock Ellis | Fifth | 24½ out |
| Saturday, July 25 |
| » Defeated Pirates (55-44), 8-4 | Three Rivers Stadium (1-1) | 44-54 | |
| » Starters: Ron Cook vs Bob Veale | Fifth | 24½ out |
| Sunday, July 26 |
| » Defeated Pirates (55-45), 6-4 | Three Rivers Stadium (2-1) | 45-54 | Won 2 |
| » Starters: Don Wilson vs Jim Nelson | Fifth | 24½ out |
| Tuesday, July 28 |
| » Defeated Cubs (50-49), 10-4 | Wrigley Field (1-3) | 46-54 | Won 3 |
| » Starters: Jack Billingham vs Milt Pappas | Fifth | 23 out |
| Wednesday, July 29 |
| » Lost to Cubs (51-49), 9-2 | Wrigley Field (1-4) | 46-55 | |
| » Starters: Larry Dierker vs Ken Holtzman | Fifth | 24 out |
| Thursday, July 30 |
| » Lost to Cubs (52-49), 6-3 | Wrigley Field (1-5) | 46-56 | Lost 2 |
| » Starters: Tom Griffin vs Fergie Jenkins | Fifth | 25 out |
| Friday, July 31 |
| » Lost to Cardinals (45-58), 5-1 | Astrodome (27-25) | 46-57 | Lost 3 |
| » Starters: Steve Carlton vs Ron Cook | Fifth | 24½ out |
| Saturday, August 1 |
| » Lost to Cardinals (46-58), 14-7 | Astrodome (27-26) | 46-58 | Lost 4 |
| » Starters: Nelson Briles vs Don Wilson | Fifth | 25½ out |
| Sunday, August 2 |
| » Lost to Cardinals (47-58), 3-2 | Astrodome (27-27) | 46-59 | Lost 5 |
| » Starters: Bob Gibson vs Jack Billingham | Fifth | 26½ out |
| Monday, August 3 |
| » Defeated Braves (50-56), 7-5 | Astrodome (28-27) | 47-59 | |
| » Starters: Phil Niekro vs Wade Blasingame | Fifth | 26 out |
| » Lost to Braves (51-56), 3-1 | Astrodome (28-28) | 47-60 | |
| » Starters: Ron Reed vs Larry Dierker | Fifth | 26 out |
| Tuesday, August 4 |
| » Lost to Braves (52-56), 6-1 | Astrodome (28-29) | 47-61 | Lost 2 |
| » Starters: Pat Jarvis vs Ron Cook | Fifth | 27 out |
| Wednesday, August 5 |
| » Defeated Padres (43-67), 4-3 | San Diego/Jack Murphy Stadium (3-2) | 48-61 | |
| » Starters: Don Wilson vs Earl Wilson | Fifth | 26 out |
| Thursday, August 6 |
| » Defeated Padres (43-68), 8-6 | San Diego/Jack Murphy Stadium (4-2) | 49-61 | Won 2 |
| » Starters: Jack Billingham vs Danny Coombs | Fifth | 25 out |
| Friday, August 7 |
| » Defeated Giants (53-56), 11-2 | Candlestick Park (2-2) | 50-61 | Won 3 |
| » Starters: Larry Dierker vs Ron Bryant | Fifth | 25 out |
| Saturday, August 8 |
| » Lost to Giants (54-56), 6-5 | Candlestick Park (2-3) | 50-62 | |
| » Starters: Wade Blasingame vs Skip Pitlock | Fifth | 26 out |
| Sunday, August 9 |
| » Defeated Giants (54-57), 7-5 | Candlestick Park (3-3) | 51-62 | |
| » Starters: Ron Cook vs Juan Marichal | Fifth | 25 out |
| » Lost to Giants (55-57), 6-1 | Candlestick Park (3-4) | 51-63 | |
| » Starters: Don Wilson vs Gaylord Perry | Fifth | 25 out |
| » Major-league debuts: Larry Howard (Astros) |
| Tuesday, August 11 |
| » Lost to Phillies (53-60), 6-5 | Astrodome (28-30) | 51-64 | Lost 2 |
| » Starters: Jim Bunning vs Jack Billingham | Fifth | 26 out |
| Wednesday, August 12 |
| » Defeated Phillies (53-61), 4-0 | Astrodome (29-30) | 52-64 | |
| » Starters: Grant Jackson vs Larry Dierker | Fifth | 25 out |
| Thursday, August 13 |
| » Defeated Phillies (53-62), 4-3 | Astrodome (30-30) | 53-64 | Won 2 |
| » Starters: Chris Short vs Wade Blasingame | Fifth | 25 out |
| Friday, August 14 |
| » Lost to Expos (50-69), 10-2 | Astrodome (30-31) | 53-65 | |
| » Starters: Steve Renko vs Ron Cook | Fifth | 25 out |
| Saturday, August 15 |
| » Defeated Expos (50-70), 7-3 | Astrodome (31-31) | 54-65 | |
| » Starters: Carl Morton vs Don Wilson | Fifth | 25 out |
| Sunday, August 16 |
| » Lost to Expos (51-70), 5-3 | Astrodome (31-32) | 54-66 | |
| » Starters: Dan McGinn vs Jack Billingham | Fifth | 26 out |
| Tuesday, August 18 |
| » Lost to Mets (64-56), 7-1 | Shea Stadium (1-4) | 54-67 | Lost 2 |
| » Starters: Larry Dierker vs Gary Gentry | Fourth | 26½ out |
| Wednesday, August 19 |
| » Defeated Mets (64-57), 9-4 | Shea Stadium (2-4) | 55-67 | |
| » Starters: Wade Blasingame vs Tom Seaver | Fourth | 25½ out |
| Friday, August 21 |
| » Lost to Phillies (55-68), 9-3 | Shibe Park (0-3) | 55-68 | |
| » Starters: Jack Billingham vs Jim Bunning | Fifth | 25 out |
| » Defeated Phillies (55-69), 9-1 | Shibe Park (1-3) | 56-68 | |
| » Starters: Don Wilson vs Grant Jackson | Fifth | 25 out |
| Saturday, August 22 |
| » Lost to Phillies (56-69), 2-1 | Shibe Park (1-4) | 56-69 | |
| » Starters: Larry Dierker vs Chris Short | Fifth | 26 out |
| Sunday, August 23 |
| » Lost to Phillies (57-69), 4-0 | Shibe Park (1-5) | 56-70 | Lost 2 |
| » Starters: Wade Blasingame vs Rick Wise | Fifth | 26½ out |
| Tuesday, August 25 |
| » Defeated Expos (55-72), 6-3 | Parc Jarry (2-2) | 57-70 | |
| » Starters: Jack Billingham vs Carl Morton | Fifth | 25½ out |
| Wednesday, August 26 |
| » Defeated Expos (55-73), 5-4 | Parc Jarry (3-2) | 58-70 | Won 2 |
| » Starters: Don Wilson vs Steve Renko | Fifth | 25½ out |
| Thursday, August 27 |
| » Defeated Expos (55-74), 5-4 | Parc Jarry (4-2) | 59-70 | Won 3 |
| » Starters: Larry Dierker vs Mike Wegener | Fifth | 24½ out |
| Friday, August 28 |
| » Defeated Mets (67-62), 2-1 | Astrodome (32-32) | 60-70 | Won 4 |
| » Starters: Tom Seaver vs Wade Blasingame | Fifth | 23½ out |
| Saturday, August 29 |
| » Defeated Mets (67-63), 9-8 | Astrodome (33-32) | 61-70 | Won 5 |
| » Starters: Gary Gentry vs Jack Billingham | Fifth | 23½ out |
| Sunday, August 30 |
| » Defeated Mets (67-64), 9-5 | Astrodome (34-32) | 62-70 | Won 6 |
| » Starters: Nolan Ryan vs Don Wilson | Fifth | 22½ out |
| Tuesday, September 1 |
| » Lost to Padres (51-82), 2-1 | Astrodome (34-33) | 62-71 | |
| » Starters: Pat Dobson vs Larry Dierker | Fifth | 22½ out |
| Wednesday, September 2 |
| » Defeated Padres (51-83), 2-1 | Astrodome (35-33) | 63-71 | |
| » Starters: Danny Coombs vs Wade Blasingame | Fifth | 22½ out |
| Thursday, September 3 |
| » Lost to Padres (52-83), 4-0 | Astrodome (35-34) | 63-72 | |
| » Starters: Clay Kirby vs Jack Billingham | Fifth | 23½ out |
| Friday, September 4 |
| » Defeated Dodgers (74-61), 7-3 | Astrodome (36-34) | 64-72 | |
| » Starters: Sandy Vance vs Don Wilson | Fifth | 22½ out |
| Saturday, September 5 |
| » Defeated Dodgers (74-62), 7-2 | Astrodome (37-34) | 65-72 | Won 2 |
| » Starters: Claude Osteen vs Larry Dierker | Fifth | 22½ out |
| Sunday, September 6 |
| » Lost to Dodgers (75-62), 4-3 | Astrodome (37-35) | 65-73 | |
| » Starters: Joe Moeller vs Wade Blasingame | Fifth | 23½ out |
| Monday, September 7 |
| » Defeated Padres (53-86), 10-5 | San Diego/Jack Murphy Stadium (5-2) | 66-73 | |
| » Starters: Ken Forsch vs Jerry Nyman | Fifth | 21½ out |
| » Defeated Padres (53-87), 9-4 | San Diego/Jack Murphy Stadium (6-2) | 67-73 | Won 2 |
| » Starters: Jack Billingham vs Danny Coombs | Fifth | 21½ out |
| » Major-league debuts: Ken Forsch (Astros) |
| Tuesday, September 8 |
| » Defeated Padres (53-88), 8-7 | San Diego/Jack Murphy Stadium (7-2) | 68-73 | Won 3 |
| » Starters: Don Wilson vs Clay Kirby | Fifth | 21½ out |
| Wednesday, September 9 |
| » Lost to Giants (74-68), 9-5 | Candlestick Park (3-5) | 68-74 | |
| » Starters: Larry Dierker vs Ron Bryant | Fifth | 22½ out |
| Thursday, September 10 |
| » Lost to Giants (75-68), 11-0 | Candlestick Park (3-6) | 68-75 | Lost 2 |
| » Starters: Wade Blasingame vs Gaylord Perry | Fifth | 23½ out |
| Friday, September 11 |
| » Defeated Braves (71-75), 3-2 | Astrodome (38-35) | 69-75 | |
| » Starters: Jim Nash vs Jack Billingham | Fifth | 22½ out |
| Saturday, September 12 |
| » Lost to Braves (72-75), 5-3 | Astrodome (38-36) | 69-76 | |
| » Starters: Pat Jarvis vs Ken Forsch | Fifth | 22½ out |
| Sunday, September 13 |
| » Defeated Braves (72-76), 10-6 | Astrodome (39-36) | 70-76 | |
| » Starters: George Stone vs Don Wilson | Fifth | 21½ out |
| » Major-league debuts: Earl Williams (Braves) |
| Tuesday, September 15 |
| » Defeated Reds (93-57), 9-2 | Astrodome (40-36) | 71-76 | Won 2 |
| » Starters: Jim McGlothlin vs Larry Dierker | Fourth | 20½ out |
| Wednesday, September 16 |
| » Lost to Reds (94-57), 3-2 | Astrodome (40-37) | 71-77 | |
| » Starters: Gary Nolan vs Wade Blasingame | Fifth | 21½ out |
| Thursday, September 17 |
| » Defeated Dodgers (80-69), 10-5 | Dodger Stadium (5-1) | 72-77 | |
| » Starters: Ken Forsch vs Alan Foster | Fourth | 21 out |
| Friday, September 18 |
| » Lost to Dodgers (81-69), 3-2 | Dodger Stadium (5-2) | 72-78 | |
| » Starters: Jack Billingham vs Sandy Vance | Fourth | 22 out |
| Saturday, September 19 |
| » Lost to Dodgers (82-69), 6-5 | Dodger Stadium (5-3) | 72-79 | Lost 2 |
| » Starters: Don Wilson vs Claude Osteen | Fourth | 23 out |
| Sunday, September 20 |
| » Lost to Dodgers (83-69), 7-6 | Dodger Stadium (5-4) | 72-80 | Lost 3 |
| » Starters: Larry Dierker vs Don Sutton | Fifth | 23 out |
| Monday, September 21 |
| » Lost to Reds (97-58), 2-0 | Riverfront Stadium (1-4) | 72-81 | Lost 4 |
| » Starters: Ken Forsch vs Don Gullett | Fourth | 24 out |
| Tuesday, September 22 |
| » Lost to Reds (98-58), 6-5 | Riverfront Stadium (1-5) | 72-82 | Lost 5 |
| » Starters: Wade Blasingame vs Gary Nolan | Fifth | 25 out |
| Wednesday, September 23 |
| » Lost to Reds (99-58), 6-2 | Riverfront Stadium (1-6) | 72-83 | Lost 6 |
| » Starters: Jack Billingham vs Tony Cloninger | Fourth | 26 out |
| Friday, September 25 |
| » Defeated Braves (75-83), 7-4 | Atlanta-Fulton County Stadium (2-5) | 73-83 | |
| » Starters: Don Wilson vs Ron Reed | Fifth | 25 out |
| Saturday, September 26 |
| » Defeated Braves (75-84), 5-2 | Atlanta-Fulton County Stadium (3-5) | 74-83 | Won 2 |
| » Starters: Larry Dierker vs George Stone | Fourth | 25 out |
| Sunday, September 27 |
| » Defeated Braves (75-85), 10-7 | Atlanta-Fulton County Stadium (4-5) | 75-83 | Won 3 |
| » Starters: Wade Blasingame vs Steve Barber | Fourth | 25 out |
| Monday, September 28 |
| » Defeated Giants (86-73), 3-0 | Astrodome (41-37) | 76-83 | Won 4 |
| » Starters: Ron Bryant vs Jack Billingham | Fourth | 24½ out |
| Tuesday, September 29 |
| » Defeated Giants (86-74), 3-1 | Astrodome (42-37) | 77-83 | Won 5 |
| » Starters: Frank Reberger vs Don Wilson | Fourth | 23½ out |
| Wednesday, September 30 |
| » Defeated Giants (86-75), 4-3 | Astrodome (43-37) | 78-83 | Won 6 |
| » Starters: Juan Marichal |
