| Monday, April 6 |
| » Defeated Dodgers (0-1), 4-3 | Astrodome (1-0) | 1-0 | |
| » W: Mike Scott (1-0) L: Orel Hershiser (0-1) S: Dave Smith (1) | First | -- |
| » Major-league debuts: Mike Ramsey (Dodgers) |
| Tuesday, April 7 |
| » Defeated Dodgers (0-2), 6-5 | Astrodome (2-0) | 2-0 | Won 2 |
| » W: Larry Andersen (1-0) L: Matt Young (0-1) S: Dave Smith (2) | First | -- |
| » Major-league debuts: Tracy Woodson (Dodgers) |
| Wednesday, April 8 |
| » Defeated Dodgers (0-3), 7-3 | Astrodome (3-0) | 3-0 | Won 3 |
| » W: Nolan Ryan (1-0) L: Matt Young (0-2) | First | -- |
| Friday, April 10 |
| » Defeated Expos (0-3), 6-1 | Astrodome (4-0) | 4-0 | Won 4 |
| » W: Danny Darwin (1-0) L: Neal Heaton (0-1) | Second | ½ out |
| Saturday, April 11 |
| » Defeated Expos (0-4), 3-2 | Astrodome (5-0) | 5-0 | Won 5 |
| » W: Aurelio Lopez (1-0) L: Jeff Parrett (0-1) S: Dave Smith (3) | First | -- |
| Sunday, April 12 |
| » Defeated Expos (0-5), 1-0 | Astrodome (6-0) | 6-0 | Won 6 |
| » W: Bob Knepper (1-0) L: Bob Sebra (0-1) S: Dave Smith (4) | First | -- |
| Monday, April 13 |
| » Lost to Dodgers (3-5), 4-2 | Dodger Stadium (0-1) | 6-1 | |
| » W: Brian Holton (1-0) L: Nolan Ryan (1-1) | First | -- |
| » Major-league debuts: Dave Meads (Astros) |
| Tuesday, April 14 |
| » Lost to Dodgers (4-5), 3-2 | Dodger Stadium (0-2) | 6-2 | Lost 2 |
| » W: Tom Niedenfuer (1-0) L: Charlie Kerfeld (0-1) | Third | ½ out |
| Wednesday, April 15 |
| » Defeated Dodgers (4-6), 4-0 | Dodger Stadium (1-2) | 7-2 | |
| » W: Mike Scott (2-0) L: Alejandro Pena (0-1) | Second | ½ out |
| Friday, April 17 |
| » Lost to Reds (7-2), 9-8 | Riverfront Stadium (0-1) | 7-3 | |
| » W: Rob Murphy (2-0) L: Bob Knepper (1-1) S: John Franco (3) | Third | ½ out |
| Saturday, April 18 |
| » Lost to Reds (8-2), 8-0 | Riverfront Stadium (0-2) | 7-4 | Lost 2 |
| » W: Bill Gullickson (3-0) L: Nolan Ryan (1-2) | Third | 1½ out |
| Sunday, April 19 |
| » Defeated Reds (8-3), 7-3 | Riverfront Stadium (1-2) | 8-4 | |
| » W: Mike Scott (3-0) L: Tom Browning (1-2) | Third | 2 out |
| » Lost to Reds (9-3), 6-2 | Riverfront Stadium (1-3) | 8-5 | |
| » W: Ted Power (2-0) L: Danny Darwin (1-1) S: Ron Robinson (1) | Third | 2 out |
| Tuesday, April 21 |
| » Defeated Braves (6-6), 7-6 | Astrodome (7-0) | 9-5 | |
| » W: Larry Andersen (2-0) L: Gene Garber (2-2) | Third | 1½ out |
| Wednesday, April 22 |
| » Defeated Braves (6-7), 6-0 | Astrodome (8-0) | 10-5 | Won 2 |
| » W: Jim Deshaies (1-0) L: David Palmer (0-3) | Second | ½ out |
| Thursday, April 23 |
| » Defeated Braves (6-8), 5-3 | Astrodome (9-0) | 11-5 | Won 3 |
| » W: Dave Meads (1-0) L: Rick Mahler (2-1) S: Dave Smith (5) | First | -- |
| Friday, April 24 |
| » Lost to Reds (12-5), 4-3 | Astrodome (9-1) | 11-6 | |
| » W: Rob Murphy (3-1) L: Charlie Kerfeld (0-2) S: Ron Robinson (3) | Second | 1 out |
| Saturday, April 25 |
| » Lost to Reds (13-5), 3-0 | Astrodome (9-2) | 11-7 | Lost 2 |
| » W: John Franco (1-0) L: Larry Andersen (2-1) S: Frank Williams (1) | Third | 2 out |
| Sunday, April 26 |
| » Lost to Reds (14-5), 11-3 | Astrodome (9-3) | 11-8 | Lost 3 |
| » W: Mario Soto (1-0) L: Bob Knepper (1-2) | Third | 3 out |
| Monday, April 27 |
| » Defeated Mets (9-9), 11-1 | Shea Stadium (1-0) | 12-8 | |
| » W: Jim Deshaies (2-0) L: David Cone (0-2) | Third | 2½ out |
| Wednesday, April 29 |
| » Lost to Mets (10-9), 2-1 | Shea Stadium (1-1) | 12-9 | |
| » W: Sid Fernandez (4-1) L: Mike Scott (3-1) S: Jesse Orosco (6) | Third | 2½ out |
| Friday, May 1 |
| » Defeated Braves (9-13), 12-3 | Atlanta-Fulton County Stadium (1-0) | 13-9 | |
| » W: Nolan Ryan (2-2) L: Rick Mahler (2-3) | Third | 2½ out |
| Saturday, May 2 |
| » Lost to Braves (10-13), 12-4 | Atlanta-Fulton County Stadium (1-1) | 13-10 | |
| » W: Randy O'Neal (3-0) L: Jim Deshaies (2-1) S: Jim Acker (1) | Third | 2½ out |
| Sunday, May 3 |
| » Lost to Braves (11-13), 5-3 | Atlanta-Fulton County Stadium (1-2) | 13-11 | Lost 2 |
| » W: Zane Smith (3-1) L: Mike Scott (3-2) S: Jeff Dedmon (1) | Third | 3½ out |
| Tuesday, May 5 |
| » Defeated Phillies (8-16), 5-1 | Veteran's Stadium (1-0) | 14-11 | |
| » W: Danny Darwin (2-1) L: Shane Rawley (1-2) | Third | 3½ out |
| Wednesday, May 6 |
| » Defeated Phillies (8-17), 3-2 | Veteran's Stadium (2-0) | 15-11 | Won 2 |
| » W: Larry Andersen (3-1) L: Kent Tekulve (1-1) S: Dave Smith (6) | Third | 2½ out |
| Friday, May 8 |
| » Defeated Expos (12-15), 3-0 | Stade Olympique (1-0) | 16-11 | Won 3 |
| » W: Mike Scott (4-2) L: Neal Heaton (3-2) | Third | 2½ out |
| Saturday, May 9 |
| » Lost to Expos (13-15), 3-1 | Stade Olympique (1-1) | 16-12 | |
| » W: Bob Sebra (2-4) L: Jim Deshaies (2-2) S: Tim Burke (2) | Third | 3½ out |
| Sunday, May 10 |
| » Lost to Expos (14-15), 6-2 | Stade Olympique (1-2) | 16-13 | Lost 2 |
| » W: Jay Tibbs (3-4) L: Danny Darwin (2-2) S: Randy St. Claire (4) | Fourth | 3½ out |
| Monday, May 11 |
| » Lost to Phillies (11-18), 7-6 | Astrodome (9-4) | 16-14 | Lost 3 |
| » W: Dan Schatzeder (2-1) L: Larry Andersen (3-2) S: Steve Bedrosian (3) | Fourth | 4 out |
| Tuesday, May 12 |
| » Defeated Phillies (11-19), 5-2 | Astrodome (10-4) | 17-14 | |
| » W: Bob Knepper (2-2) L: Michael Jackson (0-2) S: Aurelio Lopez (1) | Fourth | 3 out |
| Wednesday, May 13 |
| » Defeated Mets (14-17), 2-1 | Astrodome (11-4) | 18-14 | Won 2 |
| » W: Dave Meads (2-0) L: Gene Walter (1-1) | Third | 2½ out |
| Thursday, May 14 |
| » Defeated Mets (14-18), 5-4 | Astrodome (12-4) | 19-14 | Won 3 |
| » W: Dave Meads (3-0) L: Gene Walter (1-2) | Third | 2½ out |
| Friday, May 15 |
| » Lost to Cubs (20-14), 3-1 | Astrodome (12-5) | 19-15 | |
| » W: Greg Maddux (3-2) L: Danny Darwin (2-3) S: Lee Smith (11) | Third | 2½ out |
| Saturday, May 16 |
| » Lost to Cubs (21-14), 2-1 | Astrodome (12-6) | 19-16 | Lost 2 |
| » W: Jamie Moyer (3-3) L: Nolan Ryan (2-3) S: Frank DiPino (1) | Second | 2½ out |
| Sunday, May 17 |
| » Lost to Cubs (22-14), 6-4 | Astrodome (12-7) | 19-17 | Lost 3 |
| » W: Mike Mason (1-2) L: Bob Knepper (2-3) S: Lee Smith (12) | Second | 2½ out |
| Monday, May 18 |
| » Defeated Pirates (16-19), 4-1 | Three Rivers Stadium (1-0) | 20-17 | |
| » W: Mike Scott (5-2) L: Bob Kipper (2-4) | Third | 2 out |
| Tuesday, May 19 |
| » Lost to Pirates (17-19), 5-2 | Three Rivers Stadium (1-1) | 20-18 | |
| » W: John Smiley (3-1) L: Dave Meads (3-1) S: Don Robinson (7) | Third | 2½ out |
| Wednesday, May 20 |
| » Lost to Pirates (18-19), 5-3 | Three Rivers Stadium (1-2) | 20-19 | Lost 2 |
| » W: Dorn Taylor (1-0) L: Danny Darwin (2-4) S: Hipolito Pena (1) | Third | 3½ out |
| Friday, May 22 |
| » Lost to Cardinals (24-14), 7-5 | Astrodome (12-8) | 20-20 | Lost 3 |
| » W: Tim Conroy (3-1) L: Nolan Ryan (2-4) S: Todd Worrell (9) | Fourth | 4½ out |
| Saturday, May 23 |
| » Lost to Cardinals (25-14), 4-3 | Astrodome (12-9) | 20-21 | Lost 4 |
| » W: Pat Perry (2-1) L: Bob Knepper (2-4) S: Todd Worrell (10) | Fourth | 4½ out |
| Sunday, May 24 |
| » Lost to Cardinals (26-14), 8-2 | Astrodome (12-10) | 20-22 | Lost 5 |
| » W: Joe Magrane (4-0) L: Mike Scott (5-3) | Fourth | 5½ out |
| Monday, May 25 |
| » Defeated Pirates (21-20), 7-2 | Astrodome (13-10) | 21-22 | |
| » W: Jim Deshaies (3-2) L: Dorn Taylor (1-1) | Fourth | 4½ out |
| Tuesday, May 26 |
| » Defeated Pirates (21-21), 10-3 | Astrodome (14-10) | 22-22 | Won 2 |
| » W: Dave Meads (4-1) L: Hipolito Pena (0-2) | Fourth | 3½ out |
| » Major-league debuts: Chuck Jackson (Astros) |
| Wednesday, May 27 |
| » Defeated Pirates (21-22), 7-2 | Astrodome (15-10) | 23-22 | Won 3 |
| » W: Aurelio Lopez (2-0) L: Don Robinson (4-2) S: Dave Smith (7) | Third | 2½ out |
| Friday, May 29 |
| » Lost to Cardinals (28-16), 8-2 | Busch Stadium II (0-1) | 23-23 | |
| » W: Lee Tunnell (2-0) L: Aurelio Lopez (2-1) | Third | 2½ out |
| Saturday, May 30 |
| » Lost to Cardinals (29-16), 3-2 | Busch Stadium II (0-2) | 23-24 | Lost 2 |
| » W: Danny Cox (5-2) L: Bob Knepper (2-5) S: Todd Worrell (11) | Fourth | 3½ out |
| Sunday, May 31 |
| » Defeated Cardinals (29-17), 8-7 | Busch Stadium II (1-2) | 24-24 | |
| » W: Jim Deshaies (4-2) L: Greg Mathews (2-4) S: Dave Smith (8) | Fourth | 3½ out |
| Monday, June 1 |
| » Defeated Cubs (28-21), 6-5 | Wrigley Field (1-0) | 25-24 | Won 2 |
| » W: Larry Andersen (4-2) L: Frank DiPino (1-1) S: Dave Smith (9) | Second | 2½ out |
| » Major-league debuts: Paul Noce (Cubs) |
| Tuesday, June 2 |
| » Lost to Cubs (29-21), 13-2 | Wrigley Field (1-1) | 25-25 | |
| » W: Mike Mason (2-2) L: Nolan Ryan (2-5) | Third | 3½ out |
| Wednesday, June 3 |
| » Lost to Cubs (30-21), 22-7 | Wrigley Field (1-2) | 25-26 | Lost 2 |
| » W: Rick Sutcliffe (8-2) L: Bob Knepper (2-6) | Third | 4½ out |
| Friday, June 5 |
| » Defeated Giants (29-24), 6-1 | Astrodome (16-10) | 26-26 | |
| » W: Mike Scott (6-3) L: Mike Krukow (1-6) | Third | 4½ out |
| Saturday, June 6 |
| » Lost to Giants (30-24), 4-3 | Astrodome (16-11) | 26-27 | |
| » W: Keith Comstock (1-0) L: Larry Andersen (4-3) | Third | 5½ out |
| Sunday, June 7 |
| » Defeated Giants (30-25), 3-0 | Astrodome (17-11) | 27-27 | |
| » W: Nolan Ryan (3-5) L: Atlee Hammaker (3-2) S: Dave Smith (10) | Third | 4½ out |
| Monday, June 8 |
| » Lost to Padres (15-43), 5-4 | Astrodome (17-12) | 27-28 | |
| » W: Craig Lefferts (1-2) L: Bob Knepper (2-7) S: Rich Gossage (3) | Third | 5½ out |
| Tuesday, June 9 |
| » Defeated Padres (15-44), 1-0 | Astrodome (18-12) | 28-28 | |
| » W: Danny Darwin (3-4) L: Dave Dravecky (1-6) S: Dave Smith (11) | Third | 4½ out |
| Wednesday, June 10 |
| » Defeated Padres (15-45), 10-1 | Astrodome (19-12) | 29-28 | Won 2 |
| » W: Mike Scott (7-3) L: Storm Davis (1-7) | Third | 3½ out |
| Thursday, June 11 |
| » Defeated Dodgers (28-31), 1-0 | Dodger Stadium (2-2) | 30-28 | Won 3 |
| » W: Jim Deshaies (5-2) L: Fernando Valenzuela (5-5) S: Dave Smith (12) | Second | 2½ out |
| Friday, June 12 |
| » Defeated Dodgers (28-32), 5-1 | Dodger Stadium (3-2) | 31-28 | Won 4 |
| » W: Nolan Ryan (4-5) L: Bob Welch (8-3) | Second | 1½ out |
| Saturday, June 13 |
| » Lost to Dodgers (29-32), 7-1 | Dodger Stadium (3-3) | 31-29 | |
| » W: Orel Hershiser (7-6) L: Bob Knepper (2-8) | Third | 2½ out |
| Sunday, June 14 |
| » Defeated Dodgers (29-33), 4-1 | Dodger Stadium (4-3) | 32-29 | |
| » W: Danny Darwin (4-4) L: Tim Leary (1-2) | Third | 2½ out |
| Monday, June 15 |
| » Defeated Reds (35-28), 4-0 | Astrodome (20-12) | 33-29 | Won 2 |
| » W: Mike Scott (8-3) L: Bill Gullickson (7-4) | Second | 1½ out |
| Tuesday, June 16 |
| » Defeated Reds (35-29), 4-1 | Astrodome (21-12) | 34-29 | Won 3 |
| » W: Jim Deshaies (6-2) L: Ted Power (5-3) S: Dave Smith (13) | Second | ½ out |
| Wednesday, June 17 |
| » Lost to Reds (36-29), 9-1 | Astrodome (21-13) | 34-30 | |
| » W: Ron Robinson (2-2) L: Nolan Ryan (4-6) S: Bill Landrum (1) | Second | 1½ out |
| Thursday, June 18 |
| » Lost to Dodgers (30-35), 6-4 | Astrodome (21-14) | 34-31 | Lost 2 |
| » W: Alejandro Pena (1-6) L: Ron Mathis (0-1) S: Brian Holton (2) | Second | 2½ out |
| Friday, June 19 |
| » Defeated Dodgers (30-36), 3-2 | Astrodome (22-14) | 35-31 | |
| » W: Dave Meads (5-1) L: Orel Hershiser (7-7) | Second | 1½ out |
| Saturday, June 20 |
| » Defeated Dodgers (30-37), 3-2 | Astrodome (23-14) | 36-31 | Won 2 |
| » W: Mike Scott (9-3) L: Tim Leary (1-3) | Second | ½ out |
| Sunday, June 21 |
| » Defeated Dodgers (30-38), 6-1 | Astrodome (24-14) | 37-31 | Won 3 |
| » W: Jim Deshaies (7-2) L: Rick Honeycutt (2-6) | Second | ½ out |
| Tuesday, June 23 |
| » Lost to Padres (23-48), 4-1 | San Diego/Jack Murphy Stadium (0-1) | 37-32 | |
| » W: Ed Whitson (8-6) L: Nolan Ryan (4-7) | Second | 1½ out |
| Wednesday, June 24 |
| » Defeated Padres (23-49), 12-7 | San Diego/Jack Murphy Stadium (1-1) | 38-32 | |
| » W: Larry Andersen (5-3) L: Lance McCullers (3-5) | Second | 1½ out |
| Thursday, June 25 |
| » Lost to Padres (24-49), 4-1 | San Diego/Jack Murphy Stadium (1-2) | 38-33 | |
| » W: Dave Dravecky (3-6) L: Mike Scott (9-4) S: Lance McCullers (9) | Second | 1½ out |
| Friday, June 26 |
| » Defeated Giants (36-36), 9-6 | Candlestick Park (1-0) | 39-33 | |
| » W: Bob Knepper (3-8) L: Mike LaCoss (6-4) S: Dave Smith (14) | Second | 1½ out |
| Saturday, June 27 |
| » Defeated Giants (36-37), 6-5 | Candlestick Park (2-0) | 40-33 | Won 2 |
| » W: Jim Deshaies (8-2) L: Kelly Downs (6-4) S: Larry Andersen (1) | Second | ½ out |
| Sunday, June 28 |
| » Lost to Giants (37-37), 8-4 | Candlestick Park (2-1) | 40-34 | |
| » W: Atlee Hammaker (4-5) L: Nolan Ryan (4-8) S: Keith Comstock (1) | Second | ½ out |
| Tuesday, June 30 |
| » Lost to Reds (42-34), 5-4 | Riverfront Stadium (1-4) | 40-35 | Lost 2 |
| » W: John Franco (5-2) L: Larry Andersen (5-4) | Second | 1½ out |
| Wednesday, July 1 |
| » Lost to Reds (43-34), 6-4 | Riverfront Stadium (1-5) | 40-36 | Lost 3 |
| » W: Bill Scherrer (1-0) L: Danny Darwin (4-5) S: John Franco (16) | Second | 2½ out |
| Thursday, July 2 |
| » Defeated Phillies (36-40), 7-6 | Veteran's Stadium (3-0) | 41-36 | |
| » W: Larry Andersen (6-4) L: Steve Bedrosian (3-2) S: Dave Smith (15) | Second | 1½ out |
| Friday, July 3 |
| » Lost to Phillies (37-40), 2-1 | Veteran's Stadium (3-1) | 41-37 | |
| » W: Bruce Ruffin (5-6) L: Nolan Ryan (4-9) S: Steve Bedrosian (21) | Second | 2½ out |
| Saturday, July 4 |
| » Lost to Phillies (38-40), 9-3 | Veteran's Stadium (3-2) | 41-38 | Lost 2 |
| » W: Tom Hume (1-0) L: Jim Deshaies (8-3) S: Michael Jackson (1) | Second | 3½ out |
| Sunday, July 5 |
| » Defeated Phillies (38-41), 8-2 | Veteran's Stadium (4-2) | 42-38 | |
| » W: Mike Scott (10-4) L: Kevin Gross (6-8) S: Larry Andersen (2) | Second | 3½ out |
| Monday, July 6 |
| » Defeated Expos (42-38), 9-3 | Astrodome (25-14) | 43-38 | Won 2 |
| » W: Danny Darwin (5-5) L: Dennis Martinez (3-1) | Second | 2½ out |
| Tuesday, July 7 |
| » Lost to Expos (43-38), 2-0 | Astrodome (25-15) | 43-39 | |
| » W: Bob Sebra (5-9) L: Bob Knepper (3-9) | Second | 2½ out |
| Wednesday, July 8 |
| » Lost to Expos (44-38), 1-0 | Astrodome (25-16) | 43-40 | Lost 2 |
| » W: Floyd Youmans (6-3) L: Nolan Ryan (4-10) | Second | 2½ out |
| » Major-league debuts: Gerald Young (Astros) |
| Thursday, July 9 |
| » Defeated Mets (44-40), 4-3 | Astrodome (26-16) | 44-40 | |
| » W: Dave Smith (1-0) L: Randy Myers (1-4) | Second | 2½ out |
| Friday, July 10 |
| » Lost to Mets (45-40), 7-3 | Astrodome (26-17) | 44-41 | |
| » W: Dwight Gooden (6-2) L: Mike Scott (10-5) S: Jesse Orosco (12) | Second | 2½ out |
| Saturday, July 11 |
| » Lost to Mets (46-40), 9-6 | Astrodome (26-18) | 44-42 | Lost 2 |
| » W: Randy Myers (2-4) L: Danny Darwin (5-6) S: Roger McDowell (11) | Second | 2½ out |
| Sunday, July 12 |
| » Lost to Mets (47-40), 5-2 | Astrodome (26-19) | 44-43 | Lost 3 |
| » W: Ron Darling (4-6) L: Bob Knepper (3-10) S: Jesse Orosco (13) | Second | 2½ out |
| Thursday, July 16 |
| » Defeated Phillies (42-45), 2-1 | Astrodome (27-19) | 45-43 | |
| » W: Danny Darwin (6-6) L: Michael Jackson (3-7) | Second | 1½ out |
| » Major-league debuts: Ken Caminiti (Astros) |
| Friday, July 17 |
| » Lost to Phillies (43-45), 2-1 | Astrodome (27-20) | 45-44 | |
| » W: Shane Rawley (11-5) L: Mike Scott (10-6) S: Steve Bedrosian (25) | Second | 2½ out |
| Saturday, July 18 |
| » Lost to Phillies (44-45), 4-2 | Astrodome (27-21) | 45-45 | Lost 2 |
| » W: Don Carman (5-7) L: Bob Knepper (3-11) S: Steve Bedrosian (26) | Second | 3½ out |
| Sunday, July 19 |
| » Lost to Phillies (45-45), 4-1 | Astrodome (27-22) | 45-46 | Lost 3 |
| » W: Bruce Ruffin (7-7) L: Nolan Ryan (4-11) | Third | 3½ out |
| Monday, July 20 |
| » Lost to Expos (52-39), 4-1 | Stade Olympique (1-3) | 45-47 | Lost 4 |
| » W: Dennis Martinez (5-1) L: Jim Deshaies (8-4) | Third | 4½ out |
| Tuesday, July 21 |
| » Defeated Expos (52-40), 4-2 | Stade Olympique (2-3) | 46-47 | |
| » W: Danny Darwin (7-6) L: Floyd Youmans (7-4) S: Dave Smith (16) | Third | 4½ out |
| Wednesday, July 22 |
| » Defeated Expos (52-41), 7-0 | Stade Olympique (3-3) | 47-47 | Won 2 |
| » W: Mike Scott (11-6) L: Bob Sebra (6-10) | Second | 3½ out |
| Former Astro Don McMahon dies in Los Angeles, CA at the age of 58. |
| Friday, July 24 |
| » Lost to Mets (52-43), 5-2 | Shea Stadium (1-2) | 47-48 | |
| » W: Sid Fernandez (10-6) L: Nolan Ryan (4-12) S: Roger McDowell (13) | Third | 4½ out |
| » Lost to Mets (53-43), 7-4 | Shea Stadium (1-3) | 47-49 | Lost 2 |
| » W: John Mitchell (2-2) L: Bob Knepper (3-12) S: Jesse Orosco (14) | Third | 4½ out |
| Saturday, July 25 |
| » Defeated Mets (53-44), 7-5 | Shea Stadium (2-3) | 48-49 | |
| » W: Jim Deshaies (9-4) L: Don Schulze (1-1) S: Dave Smith (17) | Third | 3½ out |
| Sunday, July 26 |
| » Defeated Mets (53-45), 5-2 | Shea Stadium (3-3) | 49-49 | Won 2 |
| » W: Dave Smith (2-0) L: Jesse Orosco (2-7) | Third | 2½ out |
| Monday, July 27 |
| » Major-league debuts: Tim Crews (Dodgers) |
| Tuesday, July 28 |
| » Lost to Braves (44-55), 6-1 | Atlanta-Fulton County Stadium (1-3) | 49-50 | |
| » W: Zane Smith (9-6) L: Mike Scott (11-7) | Third | 3½ out |
| Wednesday, July 29 |
| » Lost to Braves (45-55), 5-3 | Atlanta-Fulton County Stadium (1-4) | 49-51 | Lost 2 |
| » W: Charlie Puleo (4-3) L: Nolan Ryan (4-13) S: Gene Garber (10) | Third | 4½ out |
| Thursday, July 30 |
| » Defeated Braves (45-56), 8-5 | Atlanta-Fulton County Stadium (2-4) | 50-51 | |
| » W: Bob Knepper (4-12) L: Rick Mahler (6-11) S: Dave Smith (18) | Third | 3½ out |
| Friday, July 31 |
| » Lost to Padres (38-65), 6-2 | Astrodome (27-23) | 50-52 | |
| » W: Ed Whitson (10-7) L: Danny Darwin (7-7) S: Lance McCullers (10) | Third | 4½ out |
| Saturday, August 1 |
| » Lost to Padres (39-65), 6-0 | Astrodome (27-24) | 50-53 | Lost 2 |
| » W: Eric Nolte (1-0) L: Jeff Heathcock (0-1) | Third | 4½ out |
| » Major-league debuts: Eric Nolte (Padres) |
| Sunday, August 2 |
| » Defeated Padres (39-66), 6-0 | Astrodome (28-24) | 51-53 | |
| » W: Mike Scott (12-7) L: Mark Grant (2-6) | Third | 4½ out |
| Monday, August 3 |
| » Defeated Giants (53-53), 5-3 | Astrodome (29-24) | 52-53 | Won 2 |
| » W: Juan Agosto (1-0) L: Joe Price (1-2) | Third | 3½ out |
| Tuesday, August 4 |
| » Defeated Giants (53-54), 5-4 | Astrodome (30-24) | 53-53 | Won 3 |
| » W: Jeff Heathcock (1-1) L: Craig Lefferts (2-4) S: Dave Smith (19) | Second | 3½ out |
| Wednesday, August 5 |
| » Defeated Giants (53-55), 6-5 | Astrodome (31-24) | 54-53 | Won 4 |
| » W: Larry Andersen (7-4) L: Jeff Robinson (6-8) | Second | 3½ out |
| Friday, August 7 |
| » Lost to Padres (42-67), 7-1 | San Diego/Jack Murphy Stadium (1-3) | 54-54 | |
| » W: Mark Davis (6-6) L: Mike Scott (12-8) S: Lance McCullers (11) | Second | 3½ out |
| Saturday, August 8 |
| » Lost to Padres (43-67), 4-3 | San Diego/Jack Murphy Stadium (1-4) | 54-55 | Lost 2 |
| » W: Rich Gossage (3-3) L: Dave Meads (5-2) | Third | 3½ out |
| Sunday, August 9 |
| » Lost to Padres (44-67), 4-3 | San Diego/Jack Murphy Stadium (1-5) | 54-56 | Lost 3 |
| » W: Eric Show (6-13) L: Bob Knepper (4-13) S: Rich Gossage (10) | Third | 3 out |
| Monday, August 10 |
| » Lost to Giants (58-55), 6-5 | Candlestick Park (2-2) | 54-57 | Lost 4 |
| » W: Don Robinson (7-6) L: Dave Meads (5-3) | Third | 4 out |
| Tuesday, August 11 |
| » Defeated Giants (58-56), 7-3 | Candlestick Park (3-2) | 55-57 | |
| » W: Jeff Heathcock (2-1) L: Mike LaCoss (10-7) S: Larry Andersen (3) | Third | 3 out |
| Wednesday, August 12 |
| » Lost to Giants (59-56), 8-1 | Candlestick Park (3-3) | 55-58 | |
| » W: Atlee Hammaker (8-8) L: Mike Scott (12-9) S: Don Robinson (14) | Second | 3 out |
| Thursday, August 13 |
| » Lost to Giants (60-56), 7-6 | Candlestick Park (3-4) | 55-59 | Lost 2 |
| » W: Craig Lefferts (3-4) L: Rocky Childress (0-1) | Second | 4 out |
| Friday, August 14 |
| » Defeated Braves (50-65), 8-4 | Astrodome (32-24) | 56-59 | |
| » W: Bob Knepper (5-13) L: Charlie Puleo (5-5) | Third | 3½ out |
| Saturday, August 15 |
| » Defeated Braves (50-66), 8-0 | Astrodome (33-24) | 57-59 | Won 2 |
| » W: Danny Darwin (8-7) L: Rick Mahler (6-12) | Second | 3 out |
| Sunday, August 16 |
| » Defeated Braves (50-67), 6-2 | Astrodome (34-24) | 58-59 | Won 3 |
| » W: Jim Deshaies (10-4) L: Zane Smith (12-7) | Second | 3 out |
| Monday, August 17 |
| » Defeated Braves (50-68), 11-2 | Astrodome (35-24) | 59-59 | Won 4 |
| » W: Mike Scott (13-9) L: Tom Glavine (0-1) | Second | 2½ out |
| » Major-league debuts: Tom Glavine (Braves) |
| Tuesday, August 18 |
| » Defeated Cardinals (70-48), 4-0 | Astrodome (36-24) | 60-59 | Won 5 |
| » W: Nolan Ryan (5-13) L: Danny Cox (8-4) S: Dave Smith (20) | Second | 1½ out |
| Wednesday, August 19 |
| » Defeated Cardinals (70-49), 2-1 | Astrodome (37-24) | 61-59 | Won 6 |
| » W: Bob Knepper (6-13) L: Joe Magrane (6-5) S: Larry Andersen (4) | Third | 1½ out |
| Thursday, August 20 |
| » Defeated Cardinals (70-50), 5-4 | Astrodome (38-24) | 62-59 | Won 7 |
| » W: Rocky Childress (1-1) L: Ken Dayley (7-4) S: Juan Agosto (1) | Second | ½ out |
| Friday, August 21 |
| » Lost to Cubs (62-60), 7-5 | Wrigley Field (1-3) | 62-60 | |
| » W: Frank DiPino (3-2) L: Jim Deshaies (10-5) S: Lee Smith (30) | Third | 1½ out |
| Saturday, August 22 |
| » Defeated Cubs (62-61), 5-4 | Wrigley Field (2-3) | 63-60 | |
| » W: Larry Andersen (8-4) L: Frank DiPino (3-3) S: Dave Smith (21) | Second | ½ out |
| Sunday, August 23 |
| » Defeated Cubs (62-62), 4-2 | Wrigley Field (3-3) | 64-60 | Won 2 |
| » W: Jeff Heathcock (3-1) L: Rick Sutcliffe (15-6) S: Dave Smith (22) | Second | ½ out |
| Monday, August 24 |
| » Defeated Cardinals (73-51), 5-2 | Busch Stadium II (2-2) | 65-60 | Won 3 |
| » W: Bob Knepper (7-13) L: Joe Magrane (6-6) | Second | ½ out |
| Tuesday, August 25 |
| » Lost to Cardinals (74-51), 7-1 | Busch Stadium II (2-3) | 65-61 | |
| » W: Greg Mathews (9-8) L: Danny Darwin (8-8) | Second | 1½ out |
| Wednesday, August 26 |
| » Lost to Cardinals (75-51), 5-4 | Busch Stadium II (2-4) | 65-62 | Lost 2 |
| » W: Ken Dayley (8-4) L: Juan Agosto (1-1) | Second | 2½ out |
| Friday, August 28 |
| » Lost to Pirates (57-71), 4-2 | Three Rivers Stadium (1-3) | 65-63 | Lost 3 |
| » W: Bob Walk (6-2) L: Mike Scott (13-10) S: Jim Gott (5) | Second | 2½ out |
| » Major-league debuts: Jose Lind (Pirates) |
| Saturday, August 29 |
| » Lost to Pirates (58-71), 8-2 | Three Rivers Stadium (1-4) | 65-64 | Lost 4 |
| » W: Mike Bielecki (1-1) L: Nolan Ryan (5-14) | Second | 3½ out |
| Sunday, August 30 |
| » Lost to Pirates (59-71), 7-0 | Three Rivers Stadium (1-5) | 65-65 | Lost 5 |
| » W: Doug Drabek (7-10) L: Bob Knepper (7-14) | Second | 3½ out |
| Monday, August 31 |
| » Lost to Cubs (66-64), 4-3 | Astrodome (38-25) | 65-66 | Lost 6 |
| » W: Les Lancaster (5-1) L: Danny Darwin (8-9) S: Lee Smith (32) | Second | 4½ out |
| Tuesday, September 1 |
| » Lost to Cubs (67-64), 3-2 | Astrodome (38-26) | 65-67 | Lost 7 |
| » W: Jamie Moyer (11-11) L: Manny Hernandez (0-1) S: Lee Smith (33) | Second | 5½ out |
| Wednesday, September 2 |
| » Defeated Cubs (67-65), 10-1 | Astrodome (39-26) | 66-67 | |
| » W: Mike Scott (14-10) L: Rick Sutcliffe (15-7) | Second | 4½ out |
| Friday, September 4 |
| » Defeated Pirates (61-73), 2-0 | Astrodome (40-26) | 67-67 | Won 2 |
| » W: Nolan Ryan (6-14) L: Mike Bielecki (1-2) S: Juan Agosto (2) | Second | 4½ out |
| » Major-league debuts: Vicente Palacios (Pirates) |
| Saturday, September 5 |
| » Defeated Pirates (61-74), 5-1 | Astrodome (41-26) | 68-67 | Won 3 |
| » W: Bob Knepper (8-14) L: Doug Drabek (7-11) | Second | 4½ out |
| Sunday, September 6 |
| » Lost to Pirates (62-74), 4-3 | Astrodome (41-27) | 68-68 | |
| » W: Mike Dunne (10-5) L: Manny Hernandez (0-2) S: Jim Gott (7) | Second | 5½ out |
| Monday, September 7 |
| » Defeated Giants (74-64), 4-2 | Astrodome (42-27) | 69-68 | |
| » W: Mike Scott (15-10) L: Mike LaCoss (11-10) | Second | 4½ out |
| Tuesday, September 8 |
| » Lost to Giants (75-64), 6-4 | Astrodome (42-28) | 69-69 | |
| » W: Don Robinson (10-6) L: Larry Andersen (8-5) | Second | 5½ out |
| Wednesday, September 9 |
| » Defeated Giants (75-65), 4-2 | Astrodome (43-28) | 70-69 | |
| » W: Nolan Ryan (7-14) L: Atlee Hammaker (9-10) S: Dave Smith (23) | Second | 4½ out |
| Thursday, September 10 |
| » Lost to Padres (57-83), 8-7 | San Diego/Jack Murphy Stadium (1-6) | 70-70 | |
| » W: Rich Gossage (5-3) L: Manny Hernandez (0-3) | Second | 5 out |
| Friday, September 11 |
| » Lost to Padres (58-83), 11-0 | San Diego/Jack Murphy Stadium (1-7) | 70-71 | Lost 2 |
| » W: Eric Show (7-16) L: Mike Scott (15-11) | Third | 5 out |
| Sunday, September 13 |
| » Lost to Padres (59-83), 10-2 | San Diego/Jack Murphy Stadium (1-8) | 70-72 | Lost 3 |
| » W: Jimmy Jones (8-6) L: Jim Deshaies (10-6) | Third | 6½ out |
| Monday, September 14 |
| » Defeated Dodgers (60-83), 8-1 | Dodger Stadium (5-3) | 71-72 | |
| » W: Nolan Ryan (8-14) L: Shawn Hillegas (2-3) | Second | 6½ out |
| » Major-league debuts: Jack Savage (Dodgers) Troy Afenir (Astros) |
| Tuesday, September 15 |
| » Lost to Dodgers (61-83), 3-2 | Dodger Stadium (5-4) | 71-73 | |
| » W: Tim Belcher (2-1) L: Bob Knepper (8-15) S: Alejandro Pena (4) | Third | 7½ out |
| Wednesday, September 16 |
| » Lost to Giants (80-66), 7-1 | Candlestick Park (3-5) | 71-74 | Lost 2 |
| » W: Dave Dravecky (10-10) L: Mike Scott (15-12) | Third | 8½ out |
| Thursday, September 17 |
| » Lost to Giants (81-66), 4-0 | Candlestick Park (3-6) | 71-75 | Lost 3 |
| » W: Rick Reuschel (13-7) L: Danny Darwin (8-10) | Third | 9½ out |
| Friday, September 18 |
| » Lost to Padres (62-85), 2-1 | Astrodome (43-29) | 71-76 | Lost 4 |
| » W: Lance McCullers (8-8) L: Dave Smith (2-1) | Third | 10 out |
| Saturday, September 19 |
| » Lost to Padres (63-85), 2-1 | Astrodome (43-30) | 71-77 | Lost 5 |
| » W: Dave Leiper (3-1) L: Manny Hernandez (0-4) S: Lance McCullers (15) | Third | 11 out |
| Sunday, September 20 |
| » Defeated Padres (63-86), 3-2 | Astrodome (44-30) | 72-77 | |
| » W: Mike Scott (16-12) L: Mark Davis (8-8) | Third | 10 out |
| Tuesday, September 22 |
| » Lost to Braves (64-85), 6-2 | Atlanta-Fulton County Stadium (2-5) | 72-78 | |
| » W: Kevin Coffman (1-3) L: Bob Knepper (8-16) S: Chuck Cary (1) | Third | 9½ out |
| Wednesday, September 23 |
| » Lost to Braves (65-85), 5-4 | Atlanta-Fulton County Stadium (2-6) | 72-79 | Lost 2 |
| » W: Jim Acker (3-6) L: Dave Smith (2-2) | |