| Wednesday, January 24 |
| Future Astro Ross Powell is born in Grand Rapids, MI. |
| Saturday, February 10 |
| Future Astro Ryan Bowen is born in Hanford, CA. Future Astro Eddie Zosky is born in Whittier, CA. |
| Tuesday, February 13 |
| Future Astro Matt Mieske is born in Midland, MI. |
| Friday, March 8 |
| Future Astro Jim Dougherty is born in Brentwood, NY. |
| Tuesday, March 26 |
| Future Astro Shane Reynolds is born in Bastrop, LA. Future Astro Jose Vizcaino is born in San Cristobal, D.R. |
| Wednesday, April 10 |
| » Defeated Pirates (0-1), 5-4 | Astrodome (1-0) | 1-0 | |
| » Starters: Jim Bunning vs Larry Dierker | First | -- |
| » Major-league debuts: Hector Torres (Astros) |
| Thursday, April 11 |
| » Defeated Phillies (1-1), 7-3 | Astrodome (2-0) | 2-0 | Won 2 |
| » Starters: Larry Jackson vs Don Wilson | First | -- |
| Friday, April 12 |
| » Defeated Phillies (1-2), 5-2 | Astrodome (3-0) | 3-0 | Won 3 |
| » Starters: Woodie Fryman vs Denny Lemaster | First | -- |
| Saturday, April 13 |
| » Defeated Phillies (1-3), 4-3 | Astrodome (4-0) | 4-0 | Won 4 |
| » Starters: Grant Jackson vs Dave Giusti | First | -- |
| » Major-league debuts: Jeff James (Phillies) |
| Sunday, April 14 |
| » Lost to Mets (2-2), 4-0 | Astrodome (4-1) | 4-1 | |
| » Starters: Nolan Ryan vs Larry Dierker | First | -- |
| Monday, April 15 |
| » Defeated Mets (2-3), 1-0 | Astrodome (5-1) | 5-1 | |
| » Starters: Tom Seaver vs Don Wilson | First | -- |
| Wednesday, April 17 |
| » Lost to Pirates (4-2), 13-4 | Forbes Field (0-1) | 5-2 | |
| » Starters: Denny Lemaster vs Al McBean | First | -- |
| Friday, April 19 |
| » Lost to Phillies (3-6), 2-1 | Shibe Park (0-1) | 5-3 | Lost 2 |
| » Starters: Dave Giusti vs Chris Short | Second | ½ out |
| Saturday, April 20 |
| » Lost to Phillies (4-6), 7-1 | Shibe Park (0-2) | 5-4 | Lost 3 |
| » Starters: Larry Dierker vs Larry Jackson | Third | 1 out |
| » Major-league debuts: Danny Walton (Astros) |
| Sunday, April 21 |
| » Lost to Phillies (5-6), 8-0 | Shibe Park (0-3) | 5-5 | Lost 4 |
| » Starters: Don Wilson vs Woodie Fryman | Fifth | 1½ out |
| Tuesday, April 23 |
| » Lost to Mets (5-7), 3-1 | Shea Stadium (0-1) | 5-6 | Lost 5 |
| » Starters: Denny Lemaster vs Jerry Koosman | Sixth | 2½ out |
| Wednesday, April 24 |
| Future Astro Todd Jones is born in Marietta, GA. |
| Friday, April 26 |
| » Lost to Cubs (6-7), 3-2 | Wrigley Field (0-1) | 5-7 | Lost 6 |
| » Starters: Larry Dierker vs Bill Hands | Eighth | 4 out |
| Saturday, April 27 |
| » Defeated Cubs (6-8), 8-1 | Wrigley Field (1-1) | 6-7 | |
| » Starters: Dave Giusti vs Rich Nye | Sixth | 4 out |
| Sunday, April 28 |
| » Lost to Cubs (7-8), 8-4 | Wrigley Field (1-2) | 6-8 | |
| » Starters: Don Wilson vs Joe Niekro | Seventh | 5½ out |
| » Lost to Cubs (8-8), 5-2 | Wrigley Field (1-3) | 6-9 | Lost 2 |
| » Starters: Denny Lemaster vs Ken Holtzman | Seventh | 5½ out |
| Monday, April 29 |
| » Lost to Reds (8-8), 17-2 | Astrodome (5-2) | 6-10 | Lost 3 |
| » Starters: Jim Maloney vs Jim Ray | Eighth | 5½ out |
| Tuesday, April 30 |
| » Defeated Reds (8-9), 3-0 | Astrodome (6-2) | 7-10 | |
| » Starters: Gerry Arrigo vs Larry Dierker | Eighth | 5½ out |
| Wednesday, May 1 |
| » Lost to Cardinals (14-5), 3-1 | Astrodome (6-3) | 7-11 | |
| » Starters: Bob Gibson vs Dave Giusti | Eighth | 6½ out |
| Thursday, May 2 |
| » Defeated Cardinals (14-6), 4-0 | Astrodome (7-3) | 8-11 | |
| » Starters: Nelson Briles vs Denny Lemaster | Eighth | 5½ out |
| Friday, May 3 |
| » Defeated Braves (9-12), 5-3 | Astrodome (8-3) | 9-11 | Won 2 |
| » Starters: Phil Niekro vs Larry Dierker | Sixth | 4½ out |
| Saturday, May 4 |
| » Lost to Braves (10-12), 5-2 | Astrodome (8-4) | 9-12 | |
| » Starters: Ron Reed vs Don Wilson | Seventh | 5½ out |
| Sunday, May 5 |
| » Lost to Braves (11-12), 2-0 | Astrodome (8-5) | 9-13 | Lost 2 |
| » Starters: Ken Johnson vs Dave Giusti | Seventh | 5½ out |
| Monday, May 6 |
| » Defeated Giants (12-11), 10-2 | Astrodome (9-5) | 10-13 | |
| » Starters: Gaylord Perry vs Denny Lemaster | Seventh | 5½ out |
| Tuesday, May 7 |
| » Defeated Giants (12-12), 7-1 | Astrodome (10-5) | 11-13 | Won 2 |
| » Starters: Juan Marichal vs Don Wilson | Sixth | 4½ out |
| Wednesday, May 8 |
| » Lost to Giants (13-12), 3-1 | Astrodome (10-6) | 11-14 | |
| » Starters: Ray Sadecki vs Larry Dierker | Sixth | 5½ out |
| Thursday, May 9 |
| » Defeated Giants (13-13), 5-3 | Astrodome (11-6) | 12-14 | |
| » Starters: Mike McCormick vs Dave Giusti | Sixth | 5 out |
| Saturday, May 11 |
| » Lost to Cardinals (18-9), 4-3 | Busch Stadium II (0-1) | 12-15 | |
| » Starters: Denny Lemaster vs Ray Washburn | Seventh | 6 out |
| Sunday, May 12 |
| » Defeated Cardinals (18-10), 3-2 | Busch Stadium II (1-1) | 13-15 | |
| » Starters: Larry Dierker vs Bob Gibson | Eighth | 5 out |
| Tuesday, May 14 |
| » Lost to Giants (16-14), 2-1 | Candlestick Park (0-1) | 13-16 | |
| » Starters: Dave Giusti vs Mike McCormick | Eighth | 6 out |
| Wednesday, May 15 |
| » Lost to Giants (17-14), 7-3 | Candlestick Park (0-2) | 13-17 | Lost 2 |
| » Starters: Denny Lemaster vs Gaylord Perry | Ninth | 7 out |
| Thursday, May 16 |
| » Lost to Giants (18-14), 3-1 | Candlestick Park (0-3) | 13-18 | Lost 3 |
| » Starters: Don Wilson vs Juan Marichal | Tenth | 7 out |
| Friday, May 17 |
| » Lost to Dodgers (16-18), 6-0 | Dodger Stadium (0-1) | 13-19 | Lost 4 |
| » Starters: Larry Dierker vs Bill Singer | Ninth | 7 out |
| Saturday, May 18 |
| » Lost to Dodgers (17-18), 1-0 | Dodger Stadium (0-2) | 13-20 | Lost 5 |
| » Starters: Dave Giusti vs Don Drysdale | Tenth | 7 out |
| Sunday, May 19 |
| » Defeated Dodgers (17-19), 2-1 | Dodger Stadium (1-2) | 14-20 | |
| » Starters: Denny Lemaster vs Claude Osteen | Eighth | 5½ out |
| » Defeated Dodgers (17-20), 3-1 | Dodger Stadium (2-2) | 15-20 | Won 2 |
| » Starters: Mike Cuellar vs Mudcat Grant | Eighth | 5½ out |
| Future Astro Alan Zinter is born in El Paso, TX. |
| Monday, May 20 |
| » Lost to Reds (19-17), 3-2 | Crosley Field (0-1) | 15-21 | |
| » Starters: Don Wilson vs Gerry Arrigo | Tenth | 6½ out |
| Tuesday, May 21 |
| » Defeated Reds (19-18), 8-2 | Crosley Field (1-1) | 16-21 | |
| » Starters: Larry Dierker vs Milt Pappas | Eighth | 5½ out |
| Wednesday, May 22 |
| » Defeated Reds (19-19), 1-0 | Crosley Field (2-1) | 17-21 | Won 2 |
| » Starters: Dave Giusti vs Jim Maloney | Eighth | 4½ out |
| Friday, May 24 |
| » Lost to Dodgers (21-21), 9-7 | Astrodome (11-7) | 17-22 | |
| » Starters: Don Sutton vs Denny Lemaster | Ninth | 6 out |
| Saturday, May 25 |
| » Defeated Dodgers (21-22), 3-2 | Astrodome (12-7) | 18-22 | |
| » Starters: Mike Kekich vs Mike Cuellar | Ninth | 5 out |
| Sunday, May 26 |
| » Lost to Dodgers (22-22), 5-0 | Astrodome (12-8) | 18-23 | |
| » Starters: Don Drysdale vs Larry Dierker | Ninth | 5 out |
| Monday, May 27 |
| » Defeated Dodgers (22-23), 10-1 | Astrodome (13-8) | 19-23 | |
| » Starters: Claude Osteen vs Don Wilson | Ninth | 4½ out |
| Future Astro Jeff Bagwell is born in Boston, MA. |
| Tuesday, May 28 |
| » Lost to Braves (24-20), 3-1 | Atlanta-Fulton County Stadium (0-1) | 19-24 | |
| » Starters: Dave Giusti vs Pat Jarvis | Ninth | 5½ out |
| Thursday, May 30 |
| » Defeated Braves (24-21), 11-0 | Atlanta-Fulton County Stadium (1-1) | 20-24 | |
| » Starters: Mike Cuellar vs Ron Reed | Ninth | 5 out |
| Friday, May 31 |
| » Defeated Cubs (23-23), 3-1 | Astrodome (14-8) | 21-24 | Won 2 |
| » Starters: Fergie Jenkins vs Larry Dierker | Eighth | 4 out |
| Saturday, June 1 |
| » Lost to Cubs (24-23), 3-1 | Astrodome (14-9) | 21-25 | |
| » Starters: Bill Hands vs Don Wilson | Seventh | 4 out |
| Sunday, June 2 |
| » Lost to Cubs (25-23), 3-2 | Astrodome (14-10) | 21-26 | Lost 2 |
| » Starters: Ken Holtzman vs Dave Giusti | Eighth | 5½ out |
| Monday, June 3 |
| » Lost to Cardinals (28-21), 7-2 | Astrodome (14-11) | 21-27 | Lost 3 |
| » Starters: Nelson Briles vs Denny Lemaster | Eighth | 6½ out |
| Tuesday, June 4 |
| » Lost to Cardinals (29-21), 3-2 | Astrodome (14-12) | 21-28 | Lost 4 |
| » Starters: Steve Carlton vs Mike Cuellar | Ninth | 7½ out |
| Wednesday, June 5 |
| » Lost to Cardinals (30-21), 3-1 | Astrodome (14-13) | 21-29 | Lost 5 |
| » Starters: Larry Jaster vs Larry Dierker | Ninth | 8½ out |
| » Major-league debuts: Wayne Granger (Cardinals) |
| Thursday, June 6 |
| » Lost to Cardinals (31-21), 4-0 | Astrodome (14-14) | 21-30 | Lost 6 |
| » Starters: Bob Gibson vs Don Wilson | Ninth | 9½ out |
| Friday, June 7 |
| » Lost to Pirates (20-28), 5-0 | Astrodome (14-15) | 21-31 | Lost 7 |
| » Starters: Steve Blass vs Dave Giusti | Tenth | 9½ out |
| Saturday, June 8 |
| » Defeated Pirates (20-29), 3-2 | Astrodome (15-15) | 22-31 | |
| » Starters: Jim Bunning vs Denny Lemaster | Ninth | 9½ out |
| Future Astro Dave Mlicki is born in Cleveland, OH. |
| Sunday, June 9 |
| » Lost to Pirates (21-29), 3-1 | Astrodome (15-16) | 22-32 | |
| » Starters: Bob Moose vs Mike Cuellar | Tenth | 10 out |
| Tuesday, June 11 |
| » Defeated Phillies (25-26), 5-1 | Shibe Park (1-3) | 23-32 | |
| » Starters: Larry Dierker vs Rick Wise | Tenth | 10½ out |
| Thursday, June 13 |
| » Lost to Phillies (26-26), 3-2 | Shibe Park (1-4) | 23-33 | |
| » Starters: Dave Giusti vs Chris Short | Tenth | 11 out |
| Friday, June 14 |
| » Lost to Pirates (24-31), 3-0 | Forbes Field (0-2) | 23-34 | Lost 2 |
| » Starters: Denny Lemaster vs Bob Moose | Ninth | 11 out |
| Saturday, June 15 |
| » Lost to Pirates (25-31), 13-2 | Forbes Field (0-3) | 23-35 | Lost 3 |
| » Starters: Don Wilson vs Bob Veale | Tenth | 12 out |
| Sunday, June 16 |
| » Lost to Pirates (26-31), 3-1 | Forbes Field (0-4) | 23-36 | Lost 4 |
| » Starters: Mike Cuellar vs Steve Blass | Ninth | 13½ out |
| » Lost to Pirates (27-31), 11-2 | Forbes Field (0-5) | 23-37 | Lost 5 |
| » Starters: Larry Dierker vs Tommie Sisk | Ninth | 13½ out |
| Monday, June 17 |
| » Lost to Pirates (28-31), 4-3 | Forbes Field (0-6) | 23-38 | Lost 6 |
| » Starters: Dave Giusti vs Al McBean | Tenth | 14 out |
| Tuesday, June 18 |
| » Defeated Mets (29-32), 3-2 | Shea Stadium (1-1) | 24-38 | |
| » Manager: Harry Walker |
| » Starters: Denny Lemaster vs Nolan Ryan | Eighth | 13½ out |
| » Defeated Mets (29-33), 6-5 | Shea Stadium (2-1) | 25-38 | Won 2 |
| » Starters: Wade Blasingame vs Don Cardwell | Eighth | 13½ out |
| Wednesday, June 19 |
| » Lost to Mets (30-33), 8-2 | Shea Stadium (2-2) | 25-39 | |
| » Starters: Don Wilson vs Jerry Koosman | Eighth | 14½ out |
| Thursday, June 20 |
| » Lost to Mets (31-33), 5-3 | Shea Stadium (2-3) | 25-40 | Lost 2 |
| » Starters: Larry Dierker vs Tom Seaver | Ninth | 15½ out |
| Friday, June 21 |
| » Defeated Phillies (31-30), 2-1 | Astrodome (16-16) | 26-40 | |
| » Starters: Jeff James vs Mike Cuellar | Tenth | 15½ out |
| Saturday, June 22 |
| » Lost to Phillies (32-30), 7-6 | Astrodome (16-17) | 26-41 | |
| » Starters: Chris Short vs Dave Giusti | Ninth | 16½ out |
| Sunday, June 23 |
| » Defeated Phillies (32-31), 7-4 | Astrodome (17-17) | 27-41 | |
| » Starters: Woodie Fryman vs Denny Lemaster | Tenth | 16 out |
| Monday, June 24 |
| » Defeated Cubs (31-38), 3-1 | Astrodome (18-17) | 28-41 | Won 2 |
| » Starters: Rich Nye vs Larry Dierker | Tenth | 15½ out |
| Tuesday, June 25 |
| » Defeated Cubs (31-39), 4-2 | Astrodome (19-17) | 29-41 | Won 3 |
| » Starters: Joe Niekro vs Mike Cuellar | Tenth | 14½ out |
| Wednesday, June 26 |
| » Defeated Cubs (31-40), 2-1 | Astrodome (20-17) | 30-41 | Won 4 |
| » Starters: Bill Hands vs Dave Giusti | Tenth | 14 out |
| Thursday, June 27 |
| » Lost to Mets (35-36), 3-1 | Astrodome (20-18) | 30-42 | |
| » Starters: Don Cardwell vs Denny Lemaster | Ninth | 14½ out |
| Friday, June 28 |
| » Defeated Mets (35-37), 7-2 | Astrodome (21-18) | 31-42 | |
| » Starters: Nolan Ryan vs Larry Dierker | Ninth | 14½ out |
| Saturday, June 29 |
| » Defeated Mets (35-38), 2-0 | Astrodome (22-18) | 32-42 | Won 2 |
| » Starters: Jerry Koosman vs Don Wilson | Tenth | 13½ out |
| Sunday, June 30 |
| » Lost to Mets (36-38), 1-0 | Astrodome (22-19) | 32-43 | |
| » Starters: Tom Seaver vs Mike Cuellar | Tenth | 13½ out |
| Monday, July 1 |
| » Lost to Reds (38-37), 3-2 | Astrodome (22-20) | 32-44 | Lost 2 |
| » Starters: Jim Maloney vs Dave Giusti | Tenth | 14½ out |
| Tuesday, July 2 |
| » Defeated Reds (38-38), 2-0 | Astrodome (23-20) | 33-44 | |
| » Starters: Gerry Arrigo vs Denny Lemaster | Tenth | 14½ out |
| Wednesday, July 3 |
| » Lost to Reds (39-38), 9-7 | Astrodome (23-21) | 33-45 | |
| » Starters: Tony Cloninger vs Larry Dierker | Tenth | 15½ out |
| Thursday, July 4 |
| » Lost to Reds (40-38), 7-4 | Astrodome (23-22) | 33-46 | Lost 2 |
| » Starters: Gary Nolan vs Don Wilson | Tenth | 16½ out |
| Friday, July 5 |
| » Defeated Braves (41-39), 13-9 | Atlanta-Fulton County Stadium (2-1) | 34-46 | |
| » Starters: Mike Cuellar vs Ron Reed | Tenth | 16½ out |
| Saturday, July 6 |
| » Lost to Braves (42-39), 5-0 | Atlanta-Fulton County Stadium (2-2) | 34-47 | |
| » Starters: Dave Giusti vs Phil Niekro | Tenth | 18 out |
| » Lost to Braves (43-39), 2-1 | Atlanta-Fulton County Stadium (2-3) | 34-48 | Lost 2 |
| » Starters: Denny Lemaster vs Pat Jarvis | Tenth | 18 out |
| Sunday, July 7 |
| » Defeated Braves (43-40), 5-4 | Atlanta-Fulton County Stadium (3-3) | 35-48 | |
| » Starters: Larry Dierker vs Milt Pappas | Tenth | 18 out |
| Thursday, July 11 |
| » Defeated Cardinals (53-31), 5-4 | Busch Stadium II (2-1) | 36-48 | Won 2 |
| » Starters: Larry Dierker vs Nelson Briles | Tenth | 18 out |
| » Lost to Cardinals (54-31), 8-7 | Busch Stadium II (2-2) | 36-49 | |
| » Starters: Mike Cuellar vs Mel Nelson | Tenth | 18 out |
| Friday, July 12 |
| » Lost to Cardinals (55-31), 8-1 | Busch Stadium II (2-3) | 36-50 | Lost 2 |
| » Starters: Denny Lemaster vs Bob Gibson | Tenth | 19 out |
| Saturday, July 13 |
| » Lost to Cardinals (56-31), 5-4 | Busch Stadium II (2-4) | 36-51 | Lost 3 |
| » Starters: Wade Blasingame vs Steve Carlton | Ninth | 20 out |
| Sunday, July 14 |
| » Defeated Reds (42-43), 5-4 | Crosley Field (3-1) | 37-51 | |
| » Starters: Dave Giusti vs Tony Cloninger | Tenth | 19½ out |
| » Defeated Reds (42-44), 6-1 | Crosley Field (4-1) | 38-51 | Won 2 |
| » Starters: Don Wilson vs Gerry Arrigo | Tenth | 19½ out |
| Future Astro Derrick May is born in Rochester, NY. |
| Tuesday, July 16 |
| » Lost to Braves (49-40), 6-2 | Astrodome (23-23) | 38-52 | |
| » Starters: George Stone vs Denny Lemaster | Tenth | 21 out |
| Wednesday, July 17 |
| » Defeated Braves (49-41), 5-2 | Astrodome (24-23) | 39-52 | |
| » Starters: Jim Britton vs Danny Coombs | Ninth | 20½ out |
| Thursday, July 18 |
| » Lost to Braves (50-41), 7-1 | Astrodome (24-24) | 39-53 | |
| » Starters: Pat Jarvis vs Dave Giusti | Tenth | 20½ out |
| Friday, July 19 |
| » Defeated Giants (46-46), 3-1 | Candlestick Park (1-3) | 40-53 | |
| » Starters: Don Wilson vs Gaylord Perry | Tenth | 19½ out |
| Saturday, July 20 |
| » Lost to Giants (47-46), 1-0 | Candlestick Park (1-4) | 40-54 | |
| » Starters: Denny Lemaster vs Ray Sadecki | Tenth | 20½ out |
| Sunday, July 21 |
| » Defeated Giants (47-47), 2-1 | Candlestick Park (2-4) | 41-54 | |
| » Starters: John Buzhardt vs Bobby Bolin | Ninth | 20½ out |
| » Lost to Giants (48-47), 6-1 | Candlestick Park (2-5) | 41-55 | |
| » Starters: Danny Coombs vs Mike McCormick | Ninth | 20½ out |
| Monday, July 22 |
| » Defeated Dodgers (43-53), 4-0 | Dodger Stadium (3-2) | 42-55 | |
| » Starters: Dave Giusti vs Mike Kekich | Tenth | 20½ out |
| Tuesday, July 23 |
| » Lost to Dodgers (44-53), 3-1 | Dodger Stadium (3-3) | 42-56 | |
| » Starters: Mike Cuellar vs Claude Osteen | Tenth | 21½ out |
| Wednesday, July 24 |
| » Defeated Dodgers (44-54), 1-0 | Dodger Stadium (4-3) | 43-56 | |
| » Starters: Don Wilson vs Don Drysdale | Tenth | 21½ out |
| Friday, July 26 |
| » Defeated Giants (49-50), 4-1 | Astrodome (25-24) | 44-56 | Won 2 |
| » Starters: Ray Sadecki vs Denny Lemaster | Tenth | 21½ out |
| Saturday, July 27 |
| » Lost to Giants (50-50), 4-3 | Astrodome (25-25) | 44-57 | |
| » Starters: Mike McCormick vs John Buzhardt | Tenth | 22½ out |
| Sunday, July 28 |
| » Lost to Giants (51-50), 4-2 | Astrodome (25-26) | 44-58 | Lost 2 |
| » Starters: Juan Marichal vs Dave Giusti | Tenth | 22½ out |
| Monday, July 29 |
| » Defeated Dodgers (45-58), 2-0 | Astrodome (26-26) | 45-58 | |
| » Starters: Mike Kekich vs Mike Cuellar | Eighth | 22½ out |
| Tuesday, July 30 |
| » Lost to Dodgers (46-58), 3-2 | Astrodome (26-27) | 45-59 | |
| » Starters: Bill Singer vs Don Wilson | Tenth | 23½ out |
| Wednesday, July 31 |
| » Lost to Cubs (54-52), 6-1 | Wrigley Field (1-4) | 45-60 | Lost 2 |
| » Starters: Denny Lemaster vs Fergie Jenkins | Tenth | 24½ out |
| Thursday, August 1 |
| » Lost to Cubs (55-52), 4-1 | Wrigley Field (1-5) | 45-61 | Lost 3 |
| » Starters: Dave Giusti vs Joe Niekro | Tenth | 25½ out |
| Friday, August 2 |
| » Defeated Phillies (48-57), 4-3 | Astrodome (27-27) | 46-61 | |
| » Starters: Jeff James vs Larry Dierker | Tenth | 24½ out |
| Saturday, August 3 |
| » Lost to Phillies (49-57), 2-1 | Astrodome (27-28) | 46-62 | |
| » Starters: Chris Short vs Mike Cuellar | Ninth | 24½ out |
| Sunday, August 4 |
| » Lost to Phillies (50-57), 3-2 | Astrodome (27-29) | 46-63 | Lost 2 |
| » Starters: Rick Wise vs Don Wilson | Tenth | 24½ out |
| Monday, August 5 |
| » Defeated Mets (51-62), 6-5 | Astrodome (28-29) | 47-63 | |
| » Starters: Jerry Koosman vs Denny Lemaster | Ninth | 24½ out |
| Tuesday, August 6 |
| » Lost to Mets (52-62), 4-1 | Astrodome (28-30) | 47-64 | |
| » Starters: Don Cardwell vs Dave Giusti | Tenth | 24½ out |
| Wednesday, August 7 |
| » Defeated Mets (52-63), 4-3 | Astrodome (29-30) | 48-64 | |
| » Starters: Tom Seaver vs Larry Dierker | Ninth | 24½ out |
| Thursday, August 8 |
| » Lost to Pirates (55-58), 4-3 | Astrodome (29-31) | 48-65 | |
| » Starters: Bob Veale vs Mike Cuellar | Tenth | 25½ out |
| Friday, August 9 |
| » Defeated Pirates (55-59), 2-1 | Astrodome (30-31) | 49-65 | |
| » Starters: Jim Bunning vs Denny Lemaster | Tenth | 25½ out |
| Saturday, August 10 |
| » Defeated Pirates (55-60), 16-3 | Astrodome (31-31) | 50-65 | Won 2 |
| » Starters: Steve Blass vs John Buzhardt | Tenth | 26 out |
| » Lost to Pirates (56-60), 7-4 | Astrodome (31-32) | 50-66 | |
| » Starters: Al McBean vs Dave Giusti | Tenth | 26 out |
| Sunday, August 11 |
| » Defeated Pirates (56-61), 5-1 | Astrodome (32-32) | 51-66 | |
| » Starters: Tommie Sisk vs Larry Dierker | Tenth | 25 out |
| Monday, August 12 |
| Future Astro Reggie Harris is born in Waynesboro, VA. |
| Tuesday, August 13 |
| » Defeated Phillies (53-62), 5-0 | Shibe Park (2-4) | 52-66 | Won 2 |
| » Starters: Don Wilson vs Rick Wise | Tenth | 24 out |
| » Lost to Phillies (54-62), 4-2 | Shibe Park (2-5) | 52-67 | |
| » Starters: Mike Cuellar vs Jeff James | Tenth | 24 out |
| Wednesday, August 14 |
| » Lost to Phillies (55-62), 4-3 | Shibe Park (2-6) | 52-68 | Lost 2 |
| » Starters: Denny Lemaster vs Chris Short | Tenth | 25 out |
| Thursday, August 15 |
| » Defeated Phillies (55-63), 3-2 | Shibe Park (3-6) | 53-68 | |
| » Starters: Dave Giusti vs Woodie Fryman | Tenth | 25 out |
| Friday, August 16 |
| » Defeated Mets (56-67), 3-1 | Shea Stadium (3-3) | 54-68 | Won 2 |
| » Starters: Larry Dierker vs Tom Seaver | Tenth | 24 out |
| Saturday, August 17 |
| » Defeated Mets (56-68), 1-0 | Shea Stadium (4-3) | 55-68 | Won 3 |
| » Starters: Don Wilson vs Jim McAndrew | Ninth | 23 out |
| Sunday, August 18 |
| » Lost to Mets (57-68), 8-1 | Shea Stadium (4-4) | 55-69 | |
| » Starters: Mike Cuellar vs Don Cardwell | Ninth | 23½ out |
| » Defeated Mets (57-69), 5-2 | Shea Stadium (5-4) | 56-69 | |
| » Starters: Jim Ray vs Dick Selma | Ninth | 23½ out |
| Monday, August 19 |
| » Defeated Dodgers (54-69), 8-5 | Astrodome (33-32) | 57-69 | Won 2 |
| » Starters: Bill Singer vs Dave Giusti | Eighth | 23½ out |
| Tuesday, August 20 |
| » Defeated Dodgers (54-70), 8-5 | Astrodome (34-32) | 58-69 | Won 3 |
| » Starters: Don Drysdale vs Larry Dierker | Eighth | 22½ out |
| Wednesday, August 21 |
| » Defeated Dodgers (54-71), 6-1 | Astrodome (35-32) | 59-69 | Won 4 |
| » Starters: Mike Kekich vs Don Wilson | Seventh | 22½ out |
| Future Astro Tuffy Rhodes is born in Cincinnati, OH. |
| Friday, August 23 |
| » Defeated Cubs (68-62), 3-2 | Astrodome (36-32) | 60-69 | Won 5 |
| » Starters: Joe Niekro vs Mike Cuellar | Seventh | 22 out |
| Saturday, August 24 |
| » Defeated Cubs (68-63), 5-1 | Astrodome (37-32) | 61-69 | Won 6 |
| » Starters: Ken Holtzman vs Dave Giusti | Seventh | 21 out |
| Sunday, August 25 |
| » Lost to Cubs (69-63), 2-0 | Astrodome (37-33) | 61-70 | |
| » Starters: Fergie Jenkins vs Larry Dierker | Eighth | 22 out |
| Monday, August 26 |
| » Lost to Dodgers (56-74), 4-3 | Dodger Stadium (4-4) | 61-71 | Lost 2 |
| » Starters: Don Wilson vs Don Sutton | Eighth | 22 out |
| Tuesday, August 27 |
| » Defeated Dodgers (56-75), 4-2 | Dodger Stadium (5-4) | 62-71 | |
| » Starters: Denny Lemaster vs Mike Kekich | Sixth | 21 out |
| Wednesday, August 28 |
| » Lost to Giants (72-60), 4-3 | Candlestick Park (2-6) | 62-72 | |
| » Starters: Mike Cuellar vs Ray Sadecki | Seventh | 22 out |
| Thursday, August 29 |
| » Defeated Giants (72-61), 6-1 | Candlestick Park (3-6) | 63-72 | |
| » Starters: Dave Giusti vs Juan Marichal | Seventh | 22 out |
| Friday, August 30 |
| » Lost to Cubs (71-66), 5-3 | Wrigley Field (1-6) | 63-73 | |
| » Starters: Larry Dierker vs Fergie Jenkins | Seventh | 22 out |
| Saturday, August 31 |
| » Defeated Cubs (71-67), 6-2 | Wrigley Field (2-6) | 64-73 | |
| » Starters: Don Wilson vs Joe Niekro | Seventh | 22 out |
| Sunday, September 1 |
| » Lost to Cubs (72-67), 2-0 | Wrigley Field (2-7) | 64-74 | |
| » Starters: Denny Lemaster vs Bill Hands | Seventh | 23 out |
| Monday, September 2 |
| » Lost to Pirates (66-72), 6-1 | Forbes Field (0-7) | 64-75 | Lost 2 |
| » Starters: Mike Cuellar vs Bob Veale | Eighth | 24½ out |
| » Lost to Pirates (67-72), 4-3 | Forbes Field (0-8) | 64-76 | Lost 3 |
| » Starters: Dave Giusti vs Bob Moose | Eighth | 24½ out |
| Tuesday, September 3 |
| » Lost to Pirates (68-72), 3-2 | Forbes Field (0-9) | 64-77 | Lost 4 |
| » Starters: Larry Dierker vs Dock Ellis | Eighth | 25½ out |
| Friday, September 6 |
| » Lost to Braves (72-70), 7-1 | Atlanta-Fulton County Stadium (3-4) | 64-78 | Lost 5 |
| » Starters: Don Wilson vs Pat Jarvis | Eighth | 24½ out |
| Saturday, September 7 |
| » Defeated Braves (72-71), 6-3 | Atlanta-Fulton County Stadium (4-4) | 65-78 | |
| » Starters: Denny Lemaster vs Phil Niekro | Eighth | 23½ out |
| » Major-league debuts: Dusty Baker (Braves) |
| Sunday, September 8 |
| » Lost to Braves (73-71), 4-1 | Atlanta-Fulton County Stadium (4-5) | 65-79 | |
| » Starters: Dave Giusti vs Milt Pappas | Eighth | 24½ out |
| Tuesday, September 10 |
| » Defeated Reds (73-69), 3-2 | Crosley Field (5-1) | 66-79 | |
| » Starters: Don Wilson vs Gerry Arrigo | Eighth | 23½ out |
| » Lost to Reds (74-69), 4-3 | Crosley Field (5-2) | 66-80 | |
| » Starters: Mike Cuellar vs Mel Queen | Eighth | 23½ out |
| » Major-league debuts: John Mayberry (Astros) |
| Wednesday, September 11 |
| » Lost to Reds (75-69), 5-1 | Crosley Field (5-3) | 66-81 | Lost 2 |
| » Starters: Denny Lemaster vs Gary Nolan | Ninth | 25 out |
| » Lost to Reds (76-69), 11-6 | Crosley Field (5-4) | 66-82 | Lost 3 |
| » Starters: John Buzhardt vs George Culver | Ninth | 25 out |
| Friday, September 13 |
| » Defeated Cardinals (91-58), 4-2 | Astrodome (38-33) | 67-82 | |
| » Starters: Ray Washburn vs Dave Giusti | Ninth | 24 out |
| Saturday, September 14 |
| » Lost to Cardinals (92-58), 8-0 | Astrodome (38-34) | 67-83 | |
| » Starters: Nelson Briles vs Larry Dierker | Ninth | 25 out |
| Sunday, September 15 |
| » Lost to Cardinals (93-58), 7-4 | Astrodome (38-35) | 67-84 | Lost 2 |
| » Starters: Steve Carlton vs Don Wilson | Ninth | 26 out |
| Tuesday, September 17 |
| » Defeated Braves (76-76), 5-1 | Astrodome (39-35) | 68-84 | |
| » Starters: Pat Jarvis vs Mike Cuellar | Ninth | 25 out |
| Wednesday, September 18 |
| » Lost to Braves (77-76), 2-0 | Astrodome (39-36) | 68-85 | |
| » Starters: Phil Niekro vs Denny Lemaster | Ninth | 26 out |
| Thursday, September 19 |
| » Lost to Braves (78-76), 4-1 | Astrodome (39-37) | 68-86 | Lost 2 |
| » Starters: Milt Pappas vs Dave Giusti | Tenth | 26 out |
| Friday, September 20 |
| » Defeated Reds (79-74), 7-6 | Astrodome (40-37) | 69-86 | |
| » Starters: Gary Nolan vs Larry Dierker | Ninth | 25 out |
| Saturday, September 21 |
| » Lost to Reds (80-74), 5-0 | Astrodome (40-38) | 69-87 | |
| » Starters: Jim Maloney vs Don Wilson | Eighth | 25 out |
| Sunday, September 22 |
| » Defeated Reds (80-75), 6-1 | Astrodome (41-38) | 70-87 | |
| » Starters: Gerry Arrigo vs Mike Cuellar | Ninth | 24 out |
| Monday, September 23 |
| » Major-league debuts: Richie Hebner and Al Oliver (Pirates) |
| Tuesday, September 24 |
| » Lost to Giants (86-72), 5-4 | Astrodome (41-39) | 70-88 | |
| » Starters: Ray Sadecki vs Denny Lemaster | Seventh | 24 out |
| Wednesday, September 25 |
| » Defeated Giants (86-73), 3-2 | Astrodome (42-39) | 71-88 | |
| » Starters: Juan Marichal vs Dave Giusti | Eighth | 24 out |
| Friday, September 27 |
| » Lost to Cardinals (96-64), 1-0 | Busch Stadium II (2-5) | 71-89 | |
| » Starters: Larry Dierker vs Bob Gibson | |
