| Wednesday, January 19 |
| Future Astro Anthony Young is born in Houston, TX. |
| Friday, March 4 |
| Future Astro Andy Mota is born in Santo Domingo, D.R. |
| Sunday, March 20 |
| Future Astro Blas Minor is born in Merced, CA. |
| Tuesday, March 22 |
| Future Astro Sean Berry is born in Santa Monica, CA. |
| Tuesday, April 12 |
| » Lost to Dodgers (1-0), 3-2 | Dodger Stadium (0-1) | 0-1 | |
| » Starters: Robin Roberts vs Claude Osteen | Third | 1 out |
| Wednesday, April 13 |
| » Defeated Dodgers (1-1), 7-6 | Dodger Stadium (1-1) | 1-1 | |
| » Starters: Larry Dierker vs Sandy Koufax | Fourth | 1 out |
| Thursday, April 14 |
| » Defeated Dodgers (1-2), 4-2 | Dodger Stadium (2-1) | 2-1 | Won 2 |
| » Starters: Bob Bruce vs Don Sutton | Second | ½ out |
| » Major-league debuts: Don Sutton (Dodgers) Nate Colbert (Astros) |
| Friday, April 15 |
| » Lost to Giants (3-1), 6-2 | Candlestick Park (0-1) | 2-2 | |
| » Starters: Turk Farrell vs Bob Shaw | Fourth | 1½ out |
| Saturday, April 16 |
| » Lost to Giants (4-1), 7-1 | Candlestick Park (0-2) | 2-3 | Lost 2 |
| » Starters: Dave Giusti vs Juan Marichal | Fifth | 2 out |
| Sunday, April 17 |
| » Lost to Giants (5-1), 3-1 | Candlestick Park (0-3) | 2-4 | Lost 3 |
| » Starters: Barry Latman vs Bobby Bolin | Sixth | 3 out |
| Monday, April 18 |
| » Lost to Dodgers (5-2), 6-3 | Astrodome (0-1) | 2-5 | Lost 4 |
| » Starters: Don Sutton vs Robin Roberts | Fifth | 3½ out |
| Tuesday, April 19 |
| » Defeated Dodgers (5-3), 8-5 | Astrodome (1-1) | 3-5 | |
| » Starters: Don Drysdale vs Turk Farrell | Fifth | 3½ out |
| Wednesday, April 20 |
| » Lost to Dodgers (6-3), 3-2 | Astrodome (1-2) | 3-6 | |
| » Starters: Claude Osteen vs Bob Bruce | Eighth | 4½ out |
| Thursday, April 21 |
| Future Astro Chris Donnels is born in Los Angeles, CA. |
| Friday, April 22 |
| » Defeated Giants (7-2), 2-0 | Astrodome (2-2) | 4-6 | |
| » Starters: Bob Shaw vs Dave Giusti | Sixth | 4 out |
| Saturday, April 23 |
| » Defeated Giants (7-3), 4-0 | Astrodome (3-2) | 5-6 | Won 2 |
| » Starters: Bobby Bolin vs Barry Latman | Seventh | 4½ out |
| » Lost to Giants (8-3), 2-1 | Astrodome (3-3) | 5-7 | |
| » Starters: Gaylord Perry vs Robin Roberts | Seventh | 4½ out |
| Sunday, April 24 |
| » Lost to Giants (9-3), 4-2 | Astrodome (3-4) | 5-8 | Lost 2 |
| » Starters: Ron Herbel vs Larry Dierker | Fourth | 4½ out |
| Monday, April 25 |
| » Defeated Reds (2-8), 2-1 | Astrodome (4-4) | 6-8 | |
| » Starters: Jim Maloney vs Mike Cuellar | Fifth | 3½ out |
| Tuesday, April 26 |
| » Major-league debuts: Jimy Williams (Cardinals) |
| Wednesday, April 27 |
| » Defeated Cardinals (6-7), 3-1 | Astrodome (5-4) | 7-8 | Won 2 |
| » Starters: Ray Washburn vs Dave Giusti | Fourth | 3 out |
| Thursday, April 28 |
| » Defeated Cardinals (6-8), 4-2 | Astrodome (6-4) | 8-8 | Won 3 |
| » Starters: Nelson Briles vs Robin Roberts | Fifth | 3 out |
| Friday, April 29 |
| » Lost to Braves (10-7), 4-3 | Atlanta-Fulton County Stadium (0-1) | 8-9 | |
| » Starters: Barry Latman vs Denny Lemaster | Fifth | 3 out |
| Saturday, April 30 |
| » Defeated Braves (10-8), 5-4 | Atlanta-Fulton County Stadium (1-1) | 9-9 | |
| » Starters: Larry Dierker vs Ken Johnson | Fifth | 2½ out |
| Sunday, May 1 |
| » Defeated Braves (10-9), 7-1 | Atlanta-Fulton County Stadium (2-1) | 10-9 | Won 2 |
| » Starters: Mike Cuellar vs Tony Cloninger | Fourth | 2½ out |
| Tuesday, May 3 |
| » Defeated Cubs (4-13), 10-2 | Astrodome (7-4) | 11-9 | Won 3 |
| » Starters: Bill Hands vs Dave Giusti | Fourth | 2½ out |
| Wednesday, May 4 |
| » Defeated Cubs (4-14), 4-0 | Astrodome (8-4) | 12-9 | Won 4 |
| » Starters: Dick Ellsworth vs Robin Roberts | Third | 2½ out |
| Thursday, May 5 |
| » Defeated Cubs (4-15), 4-3 | Astrodome (9-4) | 13-9 | Won 5 |
| » Starters: Bill Faul vs Turk Farrell | Third | 1½ out |
| Friday, May 6 |
| » Lost to Braves (13-10), 6-0 | Astrodome (9-5) | 13-10 | |
| » Starters: Denny Lemaster vs Barry Latman | Third | 3 out |
| Saturday, May 7 |
| » Defeated Braves (13-11), 3-0 | Astrodome (10-5) | 14-10 | |
| » Starters: Wade Blasingame vs Larry Dierker | Third | 3 out |
| Sunday, May 8 |
| » Defeated Braves (13-12), 5-4 | Astrodome (11-5) | 15-10 | Won 2 |
| » Starters: Ken Johnson vs Mike Cuellar | Third | 3 out |
| Tuesday, May 10 |
| » Lost to Mets (9-10), 7-4 | Shea Stadium (0-1) | 15-11 | |
| » Starters: Dave Giusti vs Rob Gardner | Third | 4 out |
| Wednesday, May 11 |
| » Defeated Mets (9-11), 6-4 | Shea Stadium (1-1) | 16-11 | |
| » Starters: Robin Roberts vs Tug McGraw | Second | 4 out |
| Friday, May 13 |
| » Defeated Phillies (12-12), 1-0 | Shibe Park (1-0) | 17-11 | Won 2 |
| » Starters: Turk Farrell vs Chris Short | Second | 4½ out |
| Saturday, May 14 |
| » Defeated Phillies (12-13), 6-5 | Shibe Park (2-0) | 18-11 | Won 3 |
| » Starters: Larry Dierker vs Bob Buhl | Second | 3½ out |
| Sunday, May 15 |
| » Lost to Phillies (13-13), 5-2 | Shibe Park (2-1) | 18-12 | |
| » Starters: Mike Cuellar vs Larry Jackson | Second | 3½ out |
| Wednesday, May 18 |
| » Defeated Cubs (6-21), 5-1 | Wrigley Field (1-0) | 19-12 | |
| » Starters: Dave Giusti vs Ernie Broglio | Second | 2½ out |
| » Defeated Cubs (6-22), 4-2 | Wrigley Field (2-0) | 20-12 | Won 2 |
| » Starters: Robin Roberts vs Dick Ellsworth | Second | 2½ out |
| Thursday, May 19 |
| » Lost to Cubs (7-22), 7-1 | Wrigley Field (2-1) | 20-13 | |
| » Starters: Turk Farrell vs Bill Hands | Second | 2½ out |
| Friday, May 20 |
| » Lost to Phillies (16-14), 6-5 | Astrodome (11-6) | 20-14 | Lost 2 |
| » Starters: Bo Belinsky vs Larry Dierker | Second | 2½ out |
| Saturday, May 21 |
| » Defeated Phillies (16-15), 4-3 | Astrodome (12-6) | 21-14 | |
| » Starters: Chris Short vs Mike Cuellar | Second | 2½ out |
| Sunday, May 22 |
| » Lost to Phillies (17-15), 6-1 | Astrodome (12-7) | 21-15 | |
| » Starters: Jim Bunning vs Barry Latman | Second | 3 out |
| Monday, May 23 |
| » Lost to Phillies (18-15), 9-0 | Astrodome (12-8) | 21-16 | Lost 2 |
| » Starters: Larry Jackson vs Dave Giusti | Second | 3½ out |
| Tuesday, May 24 |
| » Defeated Mets (13-17), 5-3 | Astrodome (13-8) | 22-16 | |
| » Starters: Jack Fisher vs Robin Roberts | Second | 3½ out |
| Wednesday, May 25 |
| » Defeated Mets (13-18), 7-1 | Astrodome (14-8) | 23-16 | Won 2 |
| » Starters: Rob Gardner vs Larry Dierker | Second | 2½ out |
| Thursday, May 26 |
| » Lost to Pirates (20-17), 3-2 | Astrodome (14-9) | 23-17 | |
| » Starters: Steve Blass vs Turk Farrell | Second | 3½ out |
| Friday, May 27 |
| » Lost to Pirates (21-17), 6-0 | Astrodome (14-10) | 23-18 | Lost 2 |
| » Starters: Bob Veale vs Barry Latman | Third | 3½ out |
| Saturday, May 28 |
| » Defeated Pirates (21-18), 2-1 | Astrodome (15-10) | 24-18 | |
| » Starters: Don Cardwell vs Dave Giusti | Third | 3 out |
| » Lost to Pirates (22-18), 5-2 | Astrodome (15-11) | 24-19 | |
| » Starters: Woodie Fryman vs Robin Roberts | Third | 3 out |
| Sunday, May 29 |
| » Defeated Pirates (22-19), 3-2 | Astrodome (16-11) | 25-19 | |
| » Starters: Vern Law vs Larry Dierker | Third | 3 out |
| Monday, May 30 |
| » Lost to Cardinals (19-21), 3-1 | Busch Stadium II (0-1) | 25-20 | |
| » Starters: Turk Farrell vs Bob Gibson | Fourth | 4 out |
| Tuesday, May 31 |
| » Lost to Cardinals (20-21), 3-0 | Busch Stadium II (0-2) | 25-21 | Lost 2 |
| » Starters: Barry Latman vs Ray Washburn | Fourth | 5 out |
| Wednesday, June 1 |
| » Defeated Reds (19-22), 2-0 | Crosley Field (1-0) | 26-21 | |
| » Starters: Dave Giusti vs Jim Maloney | Fourth | 5 out |
| Thursday, June 2 |
| » Defeated Reds (19-23), 11-4 | Crosley Field (2-0) | 27-21 | Won 2 |
| » Starters: Mike Cuellar vs Jim O'Toole | Fourth | 5 out |
| Friday, June 3 |
| » Lost to Pirates (27-20), 7-2 | Forbes Field (0-1) | 27-22 | |
| » Starters: Larry Dierker vs Woodie Fryman | Fifth | 5 out |
| Saturday, June 4 |
| » Lost to Pirates (28-20), 9-6 | Forbes Field (0-2) | 27-23 | Lost 2 |
| » Starters: Robin Roberts vs Steve Blass | Fifth | 5 out |
| Sunday, June 5 |
| » Lost to Pirates (29-20), 10-5 | Forbes Field (0-3) | 27-24 | Lost 3 |
| » Starters: Turk Farrell vs Bob Veale | Fifth | 6 out |
| Future Astro Bill Spiers is born in Orangeburg, SC. |
| Tuesday, June 7 |
| » Defeated Giants (33-20), 10-9 | Astrodome (17-11) | 28-24 | |
| » Starters: Ray Sadecki vs Dave Giusti | Fifth | 4½ out |
| Wednesday, June 8 |
| » Defeated Giants (33-21), 6-1 | Astrodome (18-11) | 29-24 | Won 2 |
| » Starters: Juan Marichal vs Mike Cuellar | Fourth | 3½ out |
| Thursday, June 9 |
| » Lost to Giants (34-21), 3-1 | Astrodome (18-12) | 29-25 | |
| » Starters: Ron Herbel vs Larry Dierker | Fourth | 4½ out |
| Friday, June 10 |
| » Defeated Cubs (16-36), 1-0 | Astrodome (19-12) | 30-25 | |
| » Starters: Ken Holtzman vs Turk Farrell | Fourth | 3½ out |
| Saturday, June 11 |
| » Lost to Cubs (17-36), 8-2 | Astrodome (19-13) | 30-26 | |
| » Starters: Bill Hands vs Bob Bruce | Fifth | 4½ out |
| Sunday, June 12 |
| » Defeated Cubs (17-37), 8-4 | Astrodome (20-13) | 31-26 | |
| » Starters: Dick Ellsworth vs Dave Giusti | Fifth | 3½ out |
| Monday, June 13 |
| » Defeated Dodgers (34-23), 9-6 | Dodger Stadium (3-1) | 32-26 | Won 2 |
| » Starters: Mike Cuellar vs Don Sutton | Fifth | 3½ out |
| Tuesday, June 14 |
| » Defeated Dodgers (34-24), 3-0 | Dodger Stadium (4-1) | 33-26 | Won 3 |
| » Starters: Larry Dierker vs Sandy Koufax | Fifth | 3½ out |
| Wednesday, June 15 |
| » Lost to Giants (38-23), 4-0 | Candlestick Park (0-4) | 33-27 | |
| » Starters: Turk Farrell vs Joe Gibbon | Fourth | 4½ out |
| Thursday, June 16 |
| » Lost to Giants (39-23), 2-1 | Candlestick Park (0-5) | 33-28 | Lost 2 |
| » Starters: Bob Bruce vs Juan Marichal | Fifth | 5½ out |
| Saturday, June 18 |
| » Defeated Cubs (18-41), 13-5 | Wrigley Field (3-1) | 34-28 | |
| » Starters: Dave Giusti vs Bill Hands | Fifth | 5 out |
| Sunday, June 19 |
| » Lost to Cubs (19-41), 9-8 | Wrigley Field (3-2) | 34-29 | |
| » Starters: Mike Cuellar vs Dick Ellsworth | Fifth | 5½ out |
| » Lost to Cubs (20-41), 8-2 | Wrigley Field (3-3) | 34-30 | Lost 2 |
| » Starters: Larry Dierker vs Ken Holtzman | Fifth | 5½ out |
| Monday, June 20 |
| » Defeated Dodgers (37-27), 4-2 | Astrodome (21-13) | 35-30 | |
| » Starters: Don Drysdale vs Robin Roberts | Fourth | 5 out |
| Tuesday, June 21 |
| » Defeated Dodgers (37-28), 7-4 | Astrodome (22-13) | 36-30 | Won 2 |
| » Starters: Don Sutton vs Turk Farrell | Fourth | 5 out |
| Wednesday, June 22 |
| » Lost to Dodgers (38-28), 5-2 | Astrodome (22-14) | 36-31 | |
| » Starters: Sandy Koufax vs Bob Bruce | Fourth | 6½ out |
| Thursday, June 23 |
| » Lost to Cardinals (33-33), 2-1 | Astrodome (22-15) | 36-32 | Lost 2 |
| » Starters: Bob Gibson vs Dave Giusti | Fourth | 7½ out |
| Friday, June 24 |
| » Defeated Cardinals (33-34), 4-1 | Astrodome (23-15) | 37-32 | |
| » Starters: Nelson Briles vs Larry Dierker | Fourth | 6½ out |
| Saturday, June 25 |
| » Defeated Cardinals (33-35), 3-2 | Astrodome (24-15) | 38-32 | Won 2 |
| » Starters: Ray Washburn vs Mike Cuellar | Fourth | 5½ out |
| Sunday, June 26 |
| » Defeated Cardinals (33-36), 6-3 | Astrodome (25-15) | 39-32 | Won 3 |
| » Starters: Al Jackson vs Turk Farrell | Fourth | 5½ out |
| Monday, June 27 |
| » Lost to Pirates (40-29), 8-5 | Forbes Field (0-4) | 39-33 | |
| » Starters: Bob Bruce vs Steve Blass | Fourth | 6½ out |
| Tuesday, June 28 |
| » Lost to Pirates (41-29), 4-3 | Forbes Field (0-5) | 39-34 | Lost 2 |
| » Starters: Dave Giusti vs Bob Veale | Fourth | 7½ out |
| Wednesday, June 29 |
| » Lost to Pirates (42-29), 6-5 | Forbes Field (0-6) | 39-35 | Lost 3 |
| » Starters: Larry Dierker vs Don Cardwell | Fifth | 7½ out |
| Thursday, June 30 |
| » Lost to Pirates (43-29), 9-0 | Forbes Field (0-7) | 39-36 | Lost 4 |
| » Starters: Robin Roberts vs Vern Law | Fifth | 8½ out |
| Friday, July 1 |
| » Defeated Reds (36-37), 2-1 | Astrodome (26-15) | 40-36 | |
| » Starters: Jim Maloney vs Mike Cuellar | Fifth | 8½ out |
| Saturday, July 2 |
| » Defeated Reds (36-38), 8-5 | Astrodome (27-15) | 41-36 | Won 2 |
| » Starters: Milt Pappas vs Turk Farrell | Fifth | 7 out |
| » Defeated Reds (36-39), 6-3 | Astrodome (28-15) | 42-36 | Won 3 |
| » Starters: Sammy Ellis vs Bob Bruce | Fifth | 7 out |
| Sunday, July 3 |
| » Defeated Reds (36-40), 3-1 | Astrodome (29-15) | 43-36 | Won 4 |
| » Starters: Hank Fischer vs Larry Dierker | Fifth | 6 out |
| Future Astro Moises Alou is born in Atlanta, GA. |
| Monday, July 4 |
| » Lost to Braves (37-45), 3-2 | Astrodome (29-16) | 43-37 | |
| » Starters: Ken Johnson vs Dave Giusti | Fifth | 6½ out |
| Tuesday, July 5 |
| » Lost to Braves (38-45), 9-4 | Astrodome (29-17) | 43-38 | Lost 2 |
| » Starters: Denny Lemaster vs Mike Cuellar | Fifth | 6½ out |
| Wednesday, July 6 |
| » Lost to Braves (39-45), 8-1 | Astrodome (29-18) | 43-39 | Lost 3 |
| » Starters: Don Schwall vs Turk Farrell | Fifth | 7½ out |
| Friday, July 8 |
| » Defeated Cardinals (38-42), 6-1 | Busch Stadium II (1-2) | 44-39 | |
| » Starters: Bob Bruce vs Bob Gibson | Fifth | 8 out |
| Saturday, July 9 |
| » Lost to Cardinals (39-42), 7-1 | Busch Stadium II (1-3) | 44-40 | |
| » Starters: Larry Dierker vs Ray Washburn | Fifth | 9 out |
| Sunday, July 10 |
| » Defeated Cardinals (39-43), 6-5 | Busch Stadium II (2-3) | 45-40 | |
| » Starters: Dave Giusti vs Al Jackson | Fifth | 8 out |
| Thursday, July 14 |
| » Lost to Braves (42-47), 7-6 | Atlanta-Fulton County Stadium (2-2) | 45-41 | |
| » Starters: Mike Cuellar vs Tony Cloninger | Fifth | 8 out |
| Saturday, July 16 |
| » Tied Braves, 1-1 | Atlanta-Fulton County Stadium (2-2) | 45-41 | |
| » Starters: Turk Farrell vs Ken Johnson | Fifth | 8 out |
| Sunday, July 17 |
| » Lost to Mets (36-51), 4-2 | Shea Stadium (1-2) | 45-42 | Lost 2 |
| » Starters: Larry Dierker vs Bob Friend | Fifth | 9 out |
| » Lost to Mets (37-51), 7-5 | Shea Stadium (1-3) | 45-43 | Lost 3 |
| » Starters: Dave Giusti vs Gerry Arrigo | Fifth | 9 out |
| Monday, July 18 |
| » Lost to Mets (38-51), 4-1 | Shea Stadium (1-4) | 45-44 | Lost 4 |
| » Starters: Mike Cuellar vs Bill Hepler | Fifth | 9½ out |
| » Lost to Mets (39-51), 6-3 | Shea Stadium (1-5) | 45-45 | Lost 5 |
| » Starters: Bob Bruce vs Bob Shaw | Fifth | 9½ out |
| Tuesday, July 19 |
| » Defeated Phillies (50-42), 8-2 | Astrodome (30-18) | 46-45 | |
| » Starters: Jim Bunning vs Turk Farrell | Fifth | 9 out |
| » Major-league debuts: John Morris (Phillies) |
| Wednesday, July 20 |
| » Lost to Phillies (51-42), 13-9 | Astrodome (30-19) | 46-46 | |
| » Starters: Bob Buhl vs Barry Latman | Fifth | 10 out |
| Thursday, July 21 |
| » Defeated Phillies (51-43), 3-2 | Astrodome (31-19) | 47-46 | |
| » Starters: Chris Short vs Dave Giusti | Fifth | 9 out |
| Friday, July 22 |
| » Defeated Pirates (56-38), 5-2 | Astrodome (32-19) | 48-46 | Won 2 |
| » Starters: Steve Blass vs Larry Dierker | Fifth | 8 out |
| Saturday, July 23 |
| » Lost to Pirates (57-38), 4-3 | Astrodome (32-20) | 48-47 | |
| » Starters: Vern Law vs Bob Bruce | Sixth | 9 out |
| Sunday, July 24 |
| » Lost to Pirates (58-38), 11-6 | Astrodome (32-21) | 48-48 | Lost 2 |
| » Starters: Tommie Sisk vs Mike Cuellar | Sixth | 10 out |
| Monday, July 25 |
| » Lost to Mets (43-54), 6-4 | Astrodome (32-22) | 48-49 | Lost 3 |
| » Starters: Dennis Ribant vs Turk Farrell | Sixth | 10 out |
| Tuesday, July 26 |
| » Lost to Mets (44-54), 5-4 | Astrodome (32-23) | 48-50 | Lost 4 |
| » Starters: Bob Shaw vs Dave Giusti | Sixth | 11 out |
| Wednesday, July 27 |
| » Lost to Mets (45-54), 3-2 | Astrodome (32-24) | 48-51 | Lost 5 |
| » Starters: Bob Friend vs Larry Dierker | Sixth | 11 out |
| Friday, July 29 |
| » Lost to Reds (48-52), 4-3 | Crosley Field (2-1) | 48-52 | Lost 6 |
| » Starters: Bob Bruce vs Jim Maloney | Sixth | 12 out |
| Saturday, July 30 |
| » Lost to Reds (49-52), 5-1 | Crosley Field (2-2) | 48-53 | Lost 7 |
| » Starters: Mike Cuellar vs Sammy Ellis | Seventh | 12 out |
| Sunday, July 31 |
| » Defeated Reds (49-53), 7-0 | Crosley Field (3-2) | 49-53 | |
| » Starters: Dave Giusti vs Milt Pappas | Seventh | 11 out |
| » Lost to Reds (50-53), 10-6 | Crosley Field (3-3) | 49-54 | |
| » Starters: Turk Farrell vs Hank Fischer | Seventh | 11 out |
| Monday, August 1 |
| » Lost to Phillies (56-49), 6-5 | Shibe Park (2-2) | 49-55 | Lost 2 |
| » Starters: Bob Bruce vs Ray Culp | Seventh | 12 out |
| Tuesday, August 2 |
| » Lost to Phillies (57-49), 4-3 | Shibe Park (2-3) | 49-56 | Lost 3 |
| » Starters: Ron Taylor vs Chris Short | Seventh | 13 out |
| Wednesday, August 3 |
| » Lost to Phillies (58-49), 7-6 | Shibe Park (2-4) | 49-57 | Lost 4 |
| » Starters: Chris Zachary vs Larry Jackson | Seventh | 14 out |
| Thursday, August 4 |
| » Lost to Phillies (59-49), 12-2 | Shibe Park (2-5) | 49-58 | Lost 5 |
| » Starters: Dave Giusti vs Jim Bunning | Seventh | 14 out |
| Friday, August 5 |
| » Lost to Dodgers (61-45), 12-1 | Astrodome (32-25) | 49-59 | Lost 6 |
| » Starters: Sandy Koufax vs Bob Bruce | Eighth | 14 out |
| Saturday, August 6 |
| » Lost to Dodgers (62-45), 4-3 | Astrodome (32-26) | 49-60 | Lost 7 |
| » Starters: Don Drysdale vs Mike Cuellar | Eighth | 15 out |
| Sunday, August 7 |
| » Lost to Dodgers (63-45), 14-3 | Astrodome (32-27) | 49-61 | Lost 8 |
| » Starters: Claude Osteen vs Turk Farrell | Eighth | 15 out |
| Monday, August 8 |
| Future Astro John Hudek is born in Tampa, FL. |
| Tuesday, August 9 |
| » Defeated Cubs (36-74), 8-5 | Wrigley Field (4-3) | 50-61 | |
| » Starters: Dave Giusti vs Dick Ellsworth | Eighth | 15 out |
| Future Astro Bob Scanlan is born in Los Angeles, CA. |
| Thursday, August 11 |
| » Lost to Cubs (37-74), 9-8 | Wrigley Field (4-4) | 50-62 | |
| » Starters: Bob Bruce vs Robin Roberts | Eighth | 16 out |
| » Defeated Cubs (37-75), 9-8 | Wrigley Field (5-4) | 51-62 | |
| » Starters: Chris Zachary vs Bill Hands | Eighth | 16 out |
| Friday, August 12 |
| » Lost to Giants (67-49), 1-0 | Candlestick Park (0-6) | 51-63 | |
| » Starters: Mike Cuellar vs Gaylord Perry | Eighth | 17 out |
| Future Astro Dean Hartgraves is born in Bakersfield, CA. |
| Saturday, August 13 |
| » Defeated Giants (67-50), 3-0 | Candlestick Park (1-6) | 52-63 | |
| » Starters: Dave Giusti vs Juan Marichal | Eighth | 16 out |
| Sunday, August 14 |
| » Lost to Giants (68-50), 5-2 | Candlestick Park (1-7) | 52-64 | |
| » Starters: Barry Latman vs Bobby Bolin | Eighth | 17½ out |
| » Lost to Giants (69-50), 5-3 | Candlestick Park (1-8) | 52-65 | Lost 2 |
| » Starters: Bob Bruce vs Joe Gibbon | Eighth | 17½ out |
| Monday, August 15 |
| » Lost to Braves (56-61), 4-2 | Astrodome (32-28) | 52-66 | Lost 3 |
| » Starters: Tony Cloninger vs Chris Zachary | Eighth | 18 out |
| Tuesday, August 16 |
| » Lost to Braves (57-61), 4-2 | Astrodome (32-29) | 52-67 | Lost 4 |
| » Starters: Dick Kelley vs Mike Cuellar | Eighth | 19 out |
| Wednesday, August 17 |
| » Lost to Braves (58-61), 6-1 | Astrodome (32-30) | 52-68 | Lost 5 |
| » Starters: Pat Jarvis vs Dave Giusti | Ninth | 19 out |
| Thursday, August 18 |
| » Defeated Reds (60-60), 5-4 | Astrodome (33-30) | 53-68 | |
| » Starters: Jim Maloney vs Bob Bruce | Ninth | 18 out |
| Friday, August 19 |
| » Defeated Reds (60-61), 4-3 | Astrodome (34-30) | 54-68 | Won 2 |
| » Starters: Milt Pappas vs Larry Dierker | Eighth | 17 out |
| Saturday, August 20 |
| » Defeated Reds (60-62), 5-2 | Astrodome (35-30) | 55-68 | Won 3 |
| » Starters: Jim O'Toole vs Mike Cuellar | Eighth | 17 out |
| Sunday, August 21 |
| » Defeated Reds (60-63), 11-0 | Astrodome (36-30) | 56-68 | Won 4 |
| » Starters: Joe Nuxhall vs Dave Giusti | Eighth | 17 out |
| Monday, August 22 |
| » Lost to Cardinals (64-60), 3-0 | Astrodome (36-31) | 56-69 | |
| » Starters: Steve Carlton vs Bob Bruce | Eighth | 18 out |
| Tuesday, August 23 |
| » Lost to Cardinals (65-60), 3-0 | Astrodome (36-32) | 56-70 | Lost 2 |
| » Starters: Bob Gibson vs Larry Dierker | Eighth | 19 out |
| Wednesday, August 24 |
| » Defeated Cardinals (65-61), 7-2 | Astrodome (37-32) | 57-70 | |
| » Starters: Larry Jaster vs Mike Cuellar | Eighth | 18 out |
| Future Astro Dean Wilkins is born in Blue Island, IL. |
| Friday, August 26 |
| » Defeated Cubs (44-83), 7-4 | Astrodome (38-32) | 58-70 | Won 2 |
| » Starters: Ken Holtzman vs Dave Giusti | Eighth | 17½ out |
| Saturday, August 27 |
| » Defeated Cubs (44-84), 5-4 | Astrodome (39-32) | 59-70 | Won 3 |
| » Starters: Dick Ellsworth vs Bob Bruce | Eighth | 17 out |
| Sunday, August 28 |
| » Defeated Cubs (44-85), 4-3 | Astrodome (40-32) | 60-70 | Won 4 |
| » Starters: Bill Hands vs Larry Dierker | Seventh | 16 out |
| Monday, August 29 |
| » Defeated Pirates (76-55), 2-0 | Forbes Field (1-7) | 61-70 | Won 5 |
| » Starters: Mike Cuellar vs Bob Veale | Seventh | 15 out |
| Tuesday, August 30 |
| » Lost to Pirates (77-55), 8-2 | Forbes Field (1-8) | 61-71 | |
| » Starters: Dave Giusti vs Woodie Fryman | Sixth | 16 out |
| Wednesday, August 31 |
| » Lost to Phillies (71-64), 10-5 | Shibe Park (2-6) | 61-72 | Lost 2 |
| » Starters: Bob Bruce vs Chris Short | Seventh | 17 out |
| Thursday, September 1 |
| » Lost to Phillies (72-64), 3-1 | Shibe Park (2-7) | 61-73 | Lost 3 |
| » Starters: Turk Farrell vs Larry Jackson | Sixth | 17 out |
| Friday, September 2 |
| » Lost to Braves (64-69), 6-5 | Atlanta-Fulton County Stadium (2-3) | 61-74 | Lost 4 |
| » Starters: Larry Dierker vs Tony Cloninger | Eighth | 18½ out |
| » Lost to Braves (65-69), 2-1 | Atlanta-Fulton County Stadium (2-4) | 61-75 | Lost 5 |
| » Starters: Chris Zachary vs Pat Jarvis | Eighth | 18½ out |
| Saturday, September 3 |
| » Lost to Braves (66-69), 12-2 | Atlanta-Fulton County Stadium (2-5) | 61-76 | Lost 6 |
| » Starters: Dave Giusti vs Charlie Vaughan | Eighth | 20 out |
| » Lost to Braves (67-69), 6-4 | Atlanta-Fulton County Stadium (2-6) | 61-77 | Lost 7 |
| » Starters: Mike Cuellar vs Ken Johnson | Eighth | 20 out |
| » Major-league debuts: Charlie Vaughan (Braves) |
| Sunday, September 4 |
| » Lost to Braves (68-69), 2-0 | Atlanta-Fulton County Stadium (2-7) | 61-78 | Lost 8 |
| » Starters: Bob Bruce vs Don Schwall | Seventh | 21 out |
| Monday, September 5 |
| » Lost to Cardinals (71-67), 4-1 | Busch Stadium II (2-4) | 61-79 | Lost 9 |
| » Starters: Turk Farrell vs Bob Gibson | Eighth | 21 out |
| » Defeated Cardinals (71-68), 6-0 | Busch Stadium II (3-4) | 62-79 | |
| » Starters: Larry Dierker vs Steve Carlton | Eighth | 21 out |
| Tuesday, September 6 |
| » Defeated Cardinals (71-69), 4-3 | Busch Stadium II (4-4) | 63-79 | Won 2 |
| » Starters: Chris Zachary vs Nelson Briles | Seventh | 20 out |
| Wednesday, September 7 |
| » Lost to Cardinals (72-69), 6-5 | Busch Stadium II (4-5) | 63-80 | |
| » Starters: Dave Giusti vs Larry Jaster | Eighth | 20 out |
| Friday, September 9 |
| » Lost to Dodgers (80-59), 7-0 | Dodger Stadium (4-2) | 63-81 | Lost 2 |
| » Starters: Bob Bruce vs Claude Osteen | Seventh | 21 out |
| » Major-league debuts: Bob Watson (Astros) |
| Saturday, September 10 |
| » Lost to Dodgers (81-59), 1-0 | Dodger Stadium (4-3) | 63-82 | Lost 3 |
| » Starters: Mike Cuellar vs Don Drysdale | Seventh | 21 out |
| Sunday, September 11 |
| » Lost to Dodgers (82-59), 4-0 | Dodger Stadium (4-4) | 63-83 | Lost 4 |
| » Starters: Larry Dierker vs Sandy Koufax | Seventh | 22½ out |
| » Lost to Dodgers (83-59), 1-0 | Dodger Stadium (4-5) | 63-84 | Lost 5 |
| » Starters: Chris Zachary vs Joe Moeller | Seventh | 22½ out |
| Tuesday, September 13 |
| » Lost to Pirates (84-61), 9-3 | Astrodome (40-33) | 63-85 | Lost 6 |
| » Starters: Tommie Sisk vs Dave Giusti | Seventh | 24 out |
| Thursday, September 15 |
| » Major-league debuts: Jim Shellenback (Pirates) |
| Friday, September 16 |
| » Defeated Phillies (79-69), 6-4 | Astrodome (41-33) | 64-85 | |
| » Starters: Chris Short vs Mike Cuellar | Eighth | 24½ out |
| Saturday, September 17 |
| » Defeated Phillies (79-70), 11-2 | Astrodome (42-33) | 65-85 | Won 2 |
| » Starters: Rick Wise vs Larry Dierker | Seventh | 23½ out |
| » Major-league debuts: Gary Sutherland (Phillies) |
| Sunday, September 18 |
| » Defeated Mets (61-89), 9-2 | Astrodome (43-33) | 66-85 | Won 3 |
| » Starters: Nolan Ryan vs Bob Bruce | Seventh | 22 out |
| » Defeated Mets (61-90), 6-5 | Astrodome (44-33) | 67-85 | Won 4 |
| » Starters: Tug McGraw vs Dave Giusti | Seventh | 22 out |
| Monday, September 19 |
| » Lost to Mets (62-90), 1-0 | Astrodome (44-34) | 67-86 | |
| » Starters: Bob Shaw vs Chris Zachary | Seventh | 23 out |
| Tuesday, September 20 |
| » Lost to Mets (63-90), 3-0 | Astrodome (44-35) | 67-87 | Lost 2 |
| » Starters: Jack Fisher vs Mike Cuellar | Eighth | 24 out |
| Friday, September 23 |
| Future Astro Pete Harnisch is born in Commack, NY. |
| Saturday, September 24 |
| » Lost to Giants (87-67), 9-5 | Astrodome (44-36) | 67-88 | Lost 3 |
| » Starters: Gaylord Perry vs Mike Cuellar | Eighth | 24½ out |
| Sunday, September 25 |
| » Defeated Giants (87-68), 5-4 | Astrodome (45-36) | 68-88 | |
| » Starters: Bobby Bolin vs Larry Dierker | Eighth | 23½ out |
| Wednesday, September 28 |
| » Lost to Reds (75-80), 7-1 | Crosley Field (3-4) | 68-89 | |
| » Starters: Dave Giusti vs Jim Maloney | Eighth | 24 out |
| » Defeated Reds (75-81), 4-3 | Crosley Field (4-4) | 69-89 | |
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