| 1991-04-09 | @ SDN | 1 | L 4-7 | 0-1 | 6 | 48,089 | John Burkett | Ed Whitson | Mike Maddux | Trevor Wilson | Larry Andersen | 4 | 7 | -3 |
| 1991-04-10 | @ SDN | 2 | L 3-4 | 0-2 | 6 | 18,590 | Buddy Black | Bruce Hurst | Bruce Hurst | Buddy Black | Craig Lefferts | 7 | 11 | -4 |
| 1991-04-11 | @ SDN | 3 | W 11-9 | 1-2 | 5 | 22,475 | Mike LaCoss | Andy Benes | Dave Righetti | Craig Lefferts | | 18 | 20 | -2 |
| 1991-04-12 | @ HOU | 4 | L 2-3 | 1-3 | 5 | 25,632 | Rick Reuschel | Mark Portugal | Mark Portugal | Rick Reuschel | Dwayne Henry | 20 | 23 | -3 |
| 1991-04-13 | @ HOU | 5 | W 16-2 | 2-3 | 5 | 22,411 | Scott Garrelts | Mike Scott | Scott Garrelts | Mike Scott | Eric Gunderson | 36 | 25 | 11 |
| 1991-04-14 | @ HOU | 6 | L 2-7 | 2-4 | 6 | 12,834 | John Burkett | Jimmy Jones | Jimmy Jones | John Burkett | | 38 | 32 | 6 |
| 1991-04-15 | vs LAN | 7 | L 1-2 | 2-5 | 6 | 55,883 | Buddy Black | Tim Belcher | Tim Belcher | Buddy Black | Jay Howell | 39 | 34 | 5 |
| 1991-04-16 | vs LAN | 8 | W 8-6 | 3-5 | 6 | 24,035 | Mike LaCoss | Ramon Martinez | Mike LaCoss | Ramon Martinez | Dave Righetti | 47 | 40 | 7 |
| 1991-04-17 | vs LAN | 9 | L 2-6 | 3-6 | 6 | 29,011 | Kelly Downs | Bob Ojeda | Bob Ojeda | Rick Reuschel | | 49 | 46 | 3 |
| 1991-04-19 | vs HOU | 10 | W 5-2 | 4-6 | 5 | 12,392 | John Burkett | Jimmy Jones | John Burkett | Jimmy Jones | Jeff Brantley | 54 | 48 | 6 |
| 1991-04-20 | vs HOU | 11 | W 4-0 | 5-6 | 5 | 18,856 | Buddy Black | Jim Deshaies | Buddy Black | Jim Deshaies | | 58 | 48 | 10 |
| 1991-04-21 | vs HOU | 12 | W 1-0 | 6-6 | 4 | 27,405 | Mike LaCoss | Pete Harnisch | Dave Righetti | Curt Schilling | | 59 | 48 | 11 |
| 1991-04-22 | vs SDN | 13 | L 5-7 | 6-7 | 5 | 12,156 | Kelly Downs | Greg Harris | Pat Clements | Trevor Wilson | Craig Lefferts | 64 | 55 | 9 |
| 1991-04-23 | vs SDN | 14 | L 6-7 | 6-8 | 6 | 12,436 | Scott Garrelts | Eric Nolte | Eric Nolte | Scott Garrelts | Craig Lefferts | 70 | 62 | 8 |
| 1991-04-24 | vs SDN | 15 | W 6-1 | 7-8 | 5 | 11,491 | John Burkett | Ed Whitson | John Burkett | Ed Whitson | | 76 | 63 | 13 |
| 1991-04-25 | @ LAN | 16 | L 1-7 | 7-9 | 6 | 38,501 | Buddy Black | Tim Belcher | Tim Belcher | Buddy Black | | 77 | 70 | 7 |
| 1991-04-26 | @ LAN | 17 | L 0-9 | 7-10 | 6 | 43,675 | Mike LaCoss | Ramon Martinez | Ramon Martinez | Mike LaCoss | | 77 | 79 | -2 |
| 1991-04-27 | @ LAN | 18 | W 4-3 | 8-10 | 5 | 48,846 | Kelly Downs | Bob Ojeda | Kelly Downs | Bob Ojeda | Jeff Brantley | 81 | 82 | -1 |
| 1991-04-28 | @ LAN | 19 | L 3-7 | 8-11 | 6 | 48,089 | John Burkett | Kevin Gross | Kevin Gross | John Burkett | | 84 | 89 | -5 |
| 1991-04-30 | @ PHI | 20 | L 9-11 | 8-12 | 6 | 15,500 | Buddy Black | Pat Combs | Joe Boever | Jeff Brantley | Mitch Williams | 93 | 100 | -7 |
| 1991-05-01 | @ PHI | 21 | L 1-4 | 8-13 | 6 | 17,281 | Mike LaCoss | Tommy Greene | Tommy Greene | Mike LaCoss | Roger McDowell | 94 | 104 | -10 |
| 1991-05-03 | @ NYN | 22 | L 0-3 | 8-14 | 6 | 28,055 | Kelly Downs | David Cone | David Cone | Kelly Downs | John Franco | 94 | 107 | -13 |
| 1991-05-04 | @ NYN | 23 | L 4-6 | 8-15 | 6 | 38,413 | John Burkett | Ron Darling | Pete Schourek | Mike LaCoss | | 98 | 113 | -15 |
| 1991-05-05 | @ NYN | 24 | W 2-0 | 9-15 | 6 | 42,576 | Buddy Black | Dwight Gooden | Buddy Black | Dwight Gooden | | 100 | 113 | -13 |
| 1991-05-06 | @ MON | 25 | L 4-10 | 9-16 | 6 | 8,699 | Don Robinson | Dennis Martinez | Dennis Martinez | Don Robinson | | 104 | 123 | -19 |
| 1991-05-07 | @ MON | 26 | L 2-3 | 9-17 | 6 | 10,197 | Kelly Downs | Chris Nabholz | Scott Ruskin | Trevor Wilson | | 106 | 126 | -20 |
| 1991-05-08 | @ MON | 27 | L 4-5 | 9-18 | 6 | 15,107 | John Burkett | Oil Can Boyd | Barry Jones | Francisco Oliveras | Tim Burke | 110 | 131 | -21 |
| 1991-05-10 | vs NYN | 28 | W 7-0 | 10-18 | 6 | 21,791 | Buddy Black | Dwight Gooden | Buddy Black | Dwight Gooden | | 117 | 131 | -14 |
| 1991-05-11 | vs NYN | 29 | L 2-6 | 10-19 | 6 | 29,006 | Don Robinson | Ron Darling | Ron Darling | Don Robinson | Alejandro Pena | 119 | 137 | -18 |
| 1991-05-12 | vs NYN | 30 | L 2-4 | 10-20 | 6 | 38,046 | Trevor Wilson | Frank Viola | John Franco | Dave Righetti | | 121 | 141 | -20 |
| 1991-05-13 | vs PHI | 31 | L 2-3 | 10-21 | 6 | 7,901 | John Burkett | Danny Cox | Joe Boever | Rod Beck | | 123 | 144 | -21 |
| 1991-05-14 | vs PHI | 32 | L 0-9 | 10-22 | 6 | 8,656 | Kelly Downs | Terry Mulholland | Terry Mulholland | Kelly Downs | | 123 | 153 | -30 |
| 1991-05-15 | vs PHI | 33 | W 4-2 | 11-22 | 6 | 12,661 | Buddy Black | Jason Grimsley | Buddy Black | Jason Grimsley | Jeff Brantley | 127 | 155 | -28 |
| 1991-05-16 | vs MON | 34 | W 5-4 | 12-22 | 6 | 8,437 | Don Robinson | Dennis Martinez | Don Robinson | Dennis Martinez | Francisco Oliveras | 132 | 159 | -27 |
| 1991-05-17 | vs MON | 35 | L 0-3 | 12-23 | 6 | 11,338 | Trevor Wilson | Rick Mahler | Barry Jones | Mike LaCoss | Scott Ruskin | 132 | 162 | -30 |
| 1991-05-18 | vs MON | 36 | L 1-3 | 12-24 | 6 | 17,579 | John Burkett | Oil Can Boyd | Oil Can Boyd | John Burkett | Tim Burke | 133 | 165 | -32 |
| 1991-05-19 | vs MON | 37 | L 4-5 | 12-25 | 6 | 29,834 | Kelly Downs | Mark Gardner | Bill Sampen | Mike LaCoss | Scott Ruskin | 137 | 170 | -33 |
| 1991-05-21 | @ CIN | 38 | L 2-3 | 12-26 | 6 | 27,358 | Buddy Black | Tom Browning | Tom Browning | Buddy Black | Rob Dibble | 139 | 173 | -34 |
| 1991-05-22 | @ CIN | 39 | L 4-9 | 12-27 | 6 | 23,053 | Don Robinson | Jose Rijo | Jose Rijo | Don Robinson | | 143 | 182 | -39 |
| 1991-05-23 | @ CIN | 40 | L 2-6 | 12-28 | 6 | 25,173 | Trevor Wilson | Jack Armstrong | Jack Armstrong | Trevor Wilson | | 145 | 188 | -43 |
| 1991-05-24 | @ ATL | 41 | L 2-3 | 12-29 | 6 | 26,313 | John Burkett | Tom Glavine | Tom Glavine | Dave Righetti | | 147 | 191 | -44 |
| 1991-05-25 | @ ATL | 42 | W 7-6 | 13-29 | 6 | 37,306 | Kelly Downs | John Smoltz | Kelly Downs | John Smoltz | Jeff Brantley | 154 | 197 | -43 |
| 1991-05-26 | @ ATL | 43 | W 10-6 | 14-29 | 6 | 34,538 | Buddy Black | Charlie Leibrandt | Buddy Black | Charlie Leibrandt | | 164 | 203 | -39 |
| 1991-05-27 | vs CIN | 44 | L 2-3 | 14-30 | 6 | 20,037 | Don Robinson | Jose Rijo | Jose Rijo | Don Robinson | Rob Dibble | 166 | 206 | -40 |
| 1991-05-28 | vs CIN | 45 | W 6-2 | 15-30 | 6 | 12,103 | Trevor Wilson | Jack Armstrong | Trevor Wilson | Jack Armstrong | | 172 | 208 | -36 |
| 1991-05-29 | vs CIN | 46 | W 6-1 | 16-30 | 6 | 19,704 | John Burkett | Chris Hammond | Francisco Oliveras | Chris Hammond | | 178 | 209 | -31 |
| 1991-05-30 | vs ATL | 47 | L 2-7 | 16-31 | 6 | 8,368 | Kelly Downs | John Smoltz | John Smoltz | Kelly Downs | | 180 | 216 | -36 |
| 1991-05-31 | vs ATL | 48 | L 2-5 | 16-32 | 6 | 14,102 | Buddy Black | Charlie Leibrandt | Charlie Leibrandt | Buddy Black | Mike Stanton | 182 | 221 | -39 |
| 1991-06-01 | vs ATL | 49 | W 8-2 | 17-32 | 6 | 26,357 | Don Robinson | Steve Avery | Don Robinson | Steve Avery | Francisco Oliveras | 190 | 223 | -33 |
| 1991-06-02 | vs ATL | 50 | W 2-1 | 18-32 | 6 | 25,162 | Trevor Wilson | Pete Smith | Trevor Wilson | Kent Mercker | Dave Righetti | 192 | 224 | -32 |
| 1991-06-04 | @ PIT | 51 | W 5-3 | 19-32 | 5 | 19,460 | John Burkett | Zane Smith | John Burkett | Zane Smith | Dave Righetti | 197 | 227 | -30 |
| 1991-06-05 | @ PIT | 52 | L 3-7 | 19-33 | 5 | 15,461 | Kelly Downs | Bob Walk | Bob Walk | Kelly Downs | | 200 | 234 | -34 |
| 1991-06-06 | @ PIT | 53 | W 6-3 | 20-33 | 5 | 23,662 | Buddy Black | John Smiley | Buddy Black | John Smiley | Dave Righetti | 206 | 237 | -31 |
| 1991-06-07 | @ SLN | 54 | W 5-2 | 21-33 | 5 | 35,017 | Don Robinson | Omar Olivares | Don Robinson | Omar Olivares | Dave Righetti | 211 | 239 | -28 |
| 1991-06-08 | @ SLN | 55 | L 2-3 | 21-34 | 5 | 38,381 | Trevor Wilson | Bob Tewksbury | Cris Carpenter | Francisco Oliveras | | 213 | 242 | -29 |
| 1991-06-09 | @ SLN | 56 | W 3-2 | 22-34 | 5 | 29,564 | John Burkett | Jose DeLeon | John Burkett | Jose DeLeon | Jeff Brantley | 216 | 244 | -28 |
| 1991-06-10 | @ SLN | 57 | L 2-3 | 22-35 | 5 | 28,829 | Scott Garrelts | Bryn Smith | Scott Terry | Jose Segura | Lee Smith | 218 | 247 | -29 |
| 1991-06-11 | @ CHN | 58 | W 8-6 | 23-35 | 5 | 32,449 | Buddy Black | Greg Maddux | Kelly Downs | Dave Smith | Dave Righetti | 226 | 253 | -27 |
| 1991-06-12 | @ CHN | 59 | L 1-6 | 23-36 | 6 | 33,880 | Don Robinson | Shawn Boskie | Shawn Boskie | Don Robinson | Dave Smith | 227 | 259 | -32 |
| 1991-06-13 | @ CHN | 60 | L 3-4 | 23-37 | 6 | 34,149 | Trevor Wilson | Bob Scanlan | Mike Bielecki | Trevor Wilson | Paul Assenmacher | 230 | 263 | -33 |
| 1991-06-14 | vs PIT | 61 | W 3-2 | 24-37 | 6 | 17,333 | John Burkett | Zane Smith | Francisco Oliveras | Zane Smith | Dave Righetti | 233 | 265 | -32 |
| 1991-06-15 | vs PIT | 62 | W 4-0 | 25-37 | 5 | 31,807 | Mike Remlinger | John Smiley | Mike Remlinger | John Smiley | | 237 | 265 | -28 |
| 1991-06-16 | vs PIT | 63 | L 3-4 | 25-38 | 6 | 27,634 | Buddy Black | Bob Walk | Bob Walk | Buddy Black | Bill Landrum | 240 | 269 | -29 |
| 1991-06-17 | vs SLN | 64 | L 4-5 | 25-39 | 6 | 12,871 | Don Robinson | Omar Olivares | Juan Agosto | Dave Righetti | Lee Smith | 244 | 274 | -30 |
| 1991-06-18 | vs SLN | 65 | L 1-3 | 25-40 | 6 | 11,140 | Trevor Wilson | Bob Tewksbury | Bob Tewksbury | Trevor Wilson | Lee Smith | 245 | 277 | -32 |
| 1991-06-19 | vs SLN | 66 | L 2-3 | 25-41 | 6 | 21,024 | John Burkett | Jose DeLeon | Jose DeLeon | John Burkett | Lee Smith | 247 | 280 | -33 |
| 1991-06-20 | vs CHN | 67 | W 4-3 | 26-41 | 5 | 16,408 | Mike Remlinger | Les Lancaster | Francisco Oliveras | Les Lancaster | Dave Righetti | 251 | 283 | -32 |
| 1991-06-21 | vs CHN | 68 | W 4-2 | 27-41 | 5 | 17,198 | Buddy Black | Greg Maddux | Kelly Downs | Greg Maddux | Dave Righetti | 255 | 285 | -30 |
| 1991-06-22 | vs CHN | 69 | W 6-3 | 28-41 | 5 | 31,841 | Trevor Wilson | Shawn Boskie | Trevor Wilson | Shawn Boskie | Francisco Oliveras | 261 | 288 | -27 |
| 1991-06-23 | vs CHN | 70 | W 2-1 | 29-41 | 5 | 42,389 | John Burkett | Bob Scanlan | Jeff Brantley | Dave Smith | | 263 | 289 | -26 |
| 1991-06-25 | @ LAN | 71 | W 9-4 | 30-41 | 5 | 44,920 | Mike Remlinger | Orel Hershiser | Mike Remlinger | Orel Hershiser | | 272 | 293 | -21 |
| 1991-06-26 | @ LAN | 72 | W 3-2 | 31-41 | 5 | 43,735 | Buddy Black | Ramon Martinez | Jeff Brantley | Tim Crews | | 275 | 295 | -20 |
| 1991-06-28 | @ SDN | 73 | L 3-5 | 31-42 | 5 | 23,524 | Don Robinson | Bruce Hurst | Bruce Hurst | Don Robinson | Larry Andersen | 278 | 300 | -22 |
| 1991-06-29 | @ SDN | 74 | W 6-4 | 32-42 | 5 | 52,488 | Trevor Wilson | Ed Whitson | Trevor Wilson | Ed Whitson | Dave Righetti | 284 | 304 | -20 |
| 1991-06-30 | @ SDN | 75 | W 8-7 | 33-42 | 5 | 23,212 | Mike Remlinger | Andy Benes | Jeff Brantley | Craig Lefferts | | 292 | 311 | -19 |
| 1991-07-02 | vs HOU | 76 | L 4-8 | 33-43 | 5 | 13,294 | Buddy Black | Mark Portugal | Mark Portugal | Buddy Black | | 296 | 319 | -23 |
| 1991-07-03 | vs HOU | 77 | L 0-9 | 33-44 | 5 | 33,774 | John Burkett | Jim Deshaies | Jim Deshaies | John Burkett | | 296 | 328 | -32 |
| 1991-07-04 | vs HOU | 78 | L 6-14 | 33-45 | 5 | 29,341 | Trevor Wilson | Darryl Kile | Darryl Kile | Trevor Wilson | | 302 | 342 | -40 |
| 1991-07-05 | vs SDN | 79 | L 2-4 | 33-46 | 5 | 13,788 | Mike Remlinger | Ed Whitson | Ed Whitson | Mike Remlinger | Mike Maddux | 304 | 346 | -42 |
| 1991-07-06 | vs SDN | 80 | W 4-1 | 34-46 | 5 | 27,706 | Don Robinson | Andy Benes | Don Robinson | Andy Benes | Dave Righetti | 308 | 347 | -39 |
| 1991-07-07 | vs SDN | 81 | W 3-0 | 35-46 | 5 | 22,568 | John Burkett | Dennis Rasmussen | John Burkett | Dennis Rasmussen | | 311 | 347 | -36 |
| 1991-07-11 | @ PHI | 82 | L 2-3 | 35-47 | 6 | 22,355 | Trevor Wilson | Terry Mulholland | Terry Mulholland | Trevor Wilson | Mitch Williams | 313 | 350 | -37 |
| 1991-07-12 | @ PHI | 83 | L 0-1 | 35-48 | 6 | 21,221 | Buddy Black | Tommy Greene | Tommy Greene | Buddy Black | Mitch Williams | 313 | 351 | -38 |
| 1991-07-13 | @ PHI | 84 | W 7-5 | 36-48 | 5 | 23,017 | John Burkett | Jose De Jesus | Francisco Oliveras | Wally Ritchie | Dave Righetti | 320 | 356 | -36 |
| 1991-07-14 | @ PHI | 85 | W 17-5 | 37-48 | 5 | 28,338 | Mike Remlinger | Danny Cox | Kelly Downs | Danny Cox | | 337 | 361 | -24 |
| 1991-07-15 | @ NYN | 86 | W 4-3 | 38-48 | 5 | 28,531 | Don Robinson | Wally Whitehurst | Don Robinson | Wally Whitehurst | Jeff Brantley | 341 | 364 | -23 |
| 1991-07-16 | @ NYN | 87 | L 4-6 | 38-49 | 5 | 33,250 | Trevor Wilson | Dwight Gooden | Dwight Gooden | Trevor Wilson | John Franco | 345 | 370 | -25 |
| 1991-07-17 | @ NYN | 88 | L 5-6 | 38-50 | 5 | 35,731 | Buddy Black | Frank Viola | Alejandro Pena | Dave Righetti | | 350 | 376 | -26 |
| 1991-07-19 | @ MON | 89 | L 0-6 | 38-51 | 5 | 15,475 | Don Robinson | Oil Can Boyd | Oil Can Boyd | Don Robinson | | 350 | 382 | -32 |
| 1991-07-20 | @ MON | 90 | W 5-3 | 39-51 | 5 | 17,285 | John Burkett | Ron Darling | John Burkett | Ron Darling | Jeff Brantley | 355 | 385 | -30 |
| 1991-07-21 | @ MON | 91 | W 3-2 | 40-51 | 5 | 16,242 | Trevor Wilson | Mark Gardner | Trevor Wilson | Mark Gardner | Jeff Brantley | 358 | 387 | -29 |
| 1991-07-23 | vs NYN | 92 | W 4-2 | 41-51 | 5 | 18,346 | Buddy Black | Frank Viola | Buddy Black | Frank Viola | Dave Righetti | 362 | 389 | -27 |
| 1991-07-24 | vs NYN | 93 | W 8-4 | 42-51 | 5 | 18,809 | John Burkett | David Cone | John Burkett | David Cone | | 370 | 393 | -23 |
| 1991-07-25 | vs NYN | 94 | W 8-1 | 43-51 | 5 | 28,992 | Trevor Wilson | Wally Whitehurst | Trevor Wilson | Wally Whitehurst | | 378 | 394 | -16 |
| 1991-07-26 | vs PHI | 95 | W 3-2 | 44-51 | 5 | 15,083 | Kelly Downs | Terry Mulholland | Kelly Downs | Terry Mulholland | Dave Righetti | 381 | 396 | -15 |
| 1991-07-27 | vs PHI | 96 | W 3-0 | 45-51 | 5 | 26,132 | Paul McClellan | Danny Cox | Paul McClellan | Danny Cox | Dave Righetti | 384 | 396 | -12 |
| 1991-07-28 | vs PHI | 97 | W 2-1 | 46-51 | 5 | 36,268 | Buddy Black | Tommy Greene | Buddy Black | Tommy Greene | Jeff Brantley | 386 | 397 | -11 |
| 1991-07-29 | vs MON | 98 | W 6-5 | 47-51 | 5 | 16,472 | John Burkett | Brian Barnes | Kelly Downs | Mel Rojas | Dave Righetti | 392 | 402 | -10 |
| 1991-07-30 | vs MON | 99 | W 10-3 | 48-51 | 4 | 19,177 | Trevor Wilson | Ron Darling | Trevor Wilson | Ron Darling | | 402 | 405 | -3 |
| 1991-08-01 | @ CIN | 100 | W 8-1 | 49-51 | 4 | 30,351 | Paul McClellan | Kip Gross | Paul McClellan | Kip Gross | | 410 | 406 | 4 |
| 1991-08-02 | @ CIN | 101 | L 4-5 | 49-52 | 4 | 33,987 | Buddy Black | Randy Myers | Randy Myers | Buddy Black | Norm Charlton | 414 | 411 | 3 |
| 1991-08-03 | @ CIN | 102 | W 7-3 | 50-52 | 4 | 46,969 | John Burkett | Jack Armstrong | John Burkett | Jack Armstrong | | 421 | 414 | 7 |
| 1991-08-04 | @ CIN | 103 | L 5-6 | 50-53 | 4 | 36,951 | Trevor Wilson | Tom Browning | Ted Power | Jeff Brantley | | 426 | 420 | 6 |
| 1991-08-05 | @ ATL | 104 | L 2-5 | 50-54 | 4 | 24,934 | Don Robinson | John Smoltz | John Smoltz | Don Robinson | | 428 | 425 | 3 |
| 1991-08-06 | @ ATL | 105 | L 6-10 | 50-55 | 4 | 27,231 | Paul McClellan | Rick Mahler | Jim Clancy | Paul McClellan | | 434 | 435 | -1 |
| 1991-08-07 | @ ATL | 106 | W 1-0 | 51-55 | 4 | 24,428 | Buddy Black | Charlie Leibrandt | Buddy Black | Charlie Leibrandt | Dave Righetti | 435 | 435 | 0 |
| 1991-08-08 | @ ATL | 107 | W 8-1 | 52-55 | 4 | 29,428 | John Burkett | Tom Glavine | John Burkett | Tom Glavine | | 443 | 436 | 7 |
| 1991-08-09 | vs LAN | 108 | W 1-0 | 53-55 | 4 | 38,111 | Trevor Wilson | Tim Belcher | Jeff Brantley | Kevin Gross | | 444 | 436 | 8 |
| 1991-08-10 | vs LAN | 109 | W 4-3 | 54-55 | 3 | 53,096 | Don Robinson | Ramon Martinez | Kelly Downs | Ramon Martinez | Dave Righetti | 448 | 439 | 9 |
| 1991-08-11 | vs LAN | 110 | W 4-3 | 55-55 | 3 | 53,759 | Paul McClellan | Orel Hershiser | Kelly Downs | Kevin Gross | Jeff Brantley | 452 | 442 | 10 |
| 1991-08-12 | vs ATL | 111 | L 1-2 | 55-56 | 3 | 22,339 | Buddy Black | Charlie Leibrandt | Charlie Leibrandt | Buddy Black | Juan Berenguer | 453 | 444 | 9 |
| 1991-08-13 | vs ATL | 112 | L 2-9 | 55-57 | 3 | 17,298 | John Burkett | Tom Glavine | Tom Glavine | John Burkett | | 455 | 453 | 2 |
| 1991-08-14 | vs ATL | 113 | W 8-3 | 56-57 | 3 | 32,284 | Trevor Wilson | Steve Avery | Trevor Wilson | Steve Avery | | 463 | 456 | 7 |
| 1991-08-15 | vs CIN | 114 | W 4-1 | 57-57 | 3 | 18,271 | Paul McClellan | Jose Rijo | Paul McClellan | Jose Rijo | Dave Righetti | 467 | 457 | 10 |
| 1991-08-16 | vs CIN | 115 | L 0-5 | 57-58 | 3 | 22,242 | Buddy Black | Kip Gross | Kip Gross | Buddy Black | | 467 | 462 | 5 |
| 1991-08-17 | vs CIN | 116 | L 0-7 | 57-59 | 3 | 34,175 | John Burkett | Scott Scudder | Scott Scudder | John Burkett | | 467 | 469 | -2 |
| 1991-08-18 | vs CIN | 117 | L 3-4 | 57-60 | 5 | 33,220 | Trevor Wilson | Tom Browning | Rob Dibble | Dave Righetti | | 470 | 473 | -3 |
| 1991-08-20 | @ HOU | 118 | W 9-3 | 58-60 | 4 | 12,201 | Paul McClellan | Jim Deshaies | Kelly Downs | Jimmy Jones | Jeff Brantley | 479 | 476 | 3 |
| 1991-08-21 | @ HOU | 119 | L 4-13 | 58-61 | 4 | 10,260 | Buddy Black | Pete Harnisch | Pete Harnisch | Buddy Black | | 483 | 489 | -6 |
| 1991-08-22 | @ HOU | 120 | W 11-8 | 59-61 | 3 | 9,411 | Don Robinson | Darryl Kile | Jeff Brantley | Darryl Kile | Dave Righetti | 494 | 497 | -3 |
| 1991-08-23 | @ PIT | 121 | L 0-8 | 59-62 | 4 | 32,419 | John Burkett | Doug Drabek | Doug Drabek | John Burkett | | 494 | 505 | -11 |
| 1991-08-24 | @ PIT | 122 | W 5-1 | 60-62 | 4 | 33,035 | Trevor Wilson | Neal Heaton | Trevor Wilson | Neal Heaton | | 499 | 506 | -7 |
| 1991-08-25 | @ PIT | 123 | L 3-8 | 60-63 | 4 | 30,453 | Francisco Oliveras | John Smiley | John Smiley | Francisco Oliveras | Stan Belinda | 502 | 514 | -12 |
| 1991-08-26 | @ SLN | 124 | L 6-7 | 60-64 | 5 | 25,554 | Buddy Black | Bryn Smith | Cris Carpenter | Buddy Black | Lee Smith | 508 | 521 | -13 |
| 1991-08-27 | @ SLN | 125 | L 4-5 | 60-65 | 5 | 23,167 | John Burkett | Bob Tewksbury | Scott Terry | Don Robinson | Lee Smith | 512 | 526 | -14 |
| 1991-08-28 | vs CHN | 126 | L 6-8 | 60-66 | 5 | 16,230 | Paul McClellan | Mike Bielecki | Mike Bielecki | Paul McClellan | Paul Assenmacher | 518 | 534 | -16 |
| 1991-08-29 | vs CHN | 127 | L 4-5 | 60-67 | 5 | 19,887 | Trevor Wilson | Greg Maddux | Greg Maddux | Francisco Oliveras | | 522 | 539 | -17 |
| 1991-08-30 | vs SLN | 128 | W 8-3 | 61-67 | 5 | 15,939 | Buddy Black | Rheal Cormier | Buddy Black | Rheal Cormier | Jeff Brantley | 530 | 542 | -12 |
| 1991-08-31 | vs SLN | 129 | W 6-1 | 62-67 | 5 | 21,546 | Bryan Hickerson | Bryn Smith | Bryan Hickerson | Bryn Smith | | 536 | 543 | -7 |
| 1991-09-01 | vs SLN | 130 | L 1-14 | 62-68 | 5 | 21,844 | John Burkett | Bob Tewksbury | Bob Tewksbury | John Burkett | | 537 | 557 | -20 |
| 1991-09-02 | vs PIT | 131 | L 8-9 | 62-69 | 5 | 16,971 | Paul McClellan | Doug Drabek | Stan Belinda | Dave Righetti | Rosario Rodriguez | 545 | 566 | -21 |
| 1991-09-03 | vs PIT | 132 | L 3-5 | 62-70 | 5 | 9,544 | Trevor Wilson | Bob Walk | Bob Patterson | Francisco Oliveras | | 548 | 571 | -23 |
| 1991-09-04 | vs PIT | 133 | L 3-8 | 62-71 | 5 | 8,690 | Buddy Black | John Smiley | John Smiley | Buddy Black | Roger Mason | 551 | 579 | -28 |
| 1991-09-06 | @ CHN | 134 | L 2-3 | 62-72 | 5 | 22,090 | Bryan Hickerson | Frank Castillo | Frank Castillo | Bryan Hickerson | Dave Smith | 553 | 582 | -29 |
| 1991-09-07 | @ CHN | 135 | L 1-2 | 62-73 | 5 | 30,821 | Paul McClellan | Mike Bielecki | Mike Bielecki | Paul McClellan | Paul Assenmacher | 554 | 584 | -30 |
| 1991-09-08 | @ CHN | 136 | W 4-3 | 63-73 | 5 | 27,875 | Trevor Wilson | Greg Maddux | Trevor Wilson | Greg Maddux | Dave Righetti | 558 | 587 | -29 |
| 1991-09-09 | @ ATL | 137 | L 3-8 | 63-74 | 5 | 19,686 | Buddy Black | John Smoltz | John Smoltz | Buddy Black | Jim Clancy | 561 | 595 | -34 |
| 1991-09-10 | @ ATL | 138 | L 1-4 | 63-75 | 5 | 23,741 | John Burkett | Steve Avery | Steve Avery | John Burkett | Alejandro Pena | 562 | 599 | -37 |
| 1991-09-11 | @ CIN | 139 | W 4-2 | 64-75 | 5 | 16,279 | Bryan Hickerson | Scott Scudder | Bryan Hickerson | Scott Scudder | Dave Righetti | 566 | 601 | -35 |
| 1991-09-12 | @ CIN | 140 | L 3-7 | 64-76 | 5 | 15,923 | Paul McClellan | Tom Browning | Tom Browning | Paul McClellan | Rob Dibble | 569 | 608 | -39 |
| 1991-09-13 | vs SDN | 141 | L 2-13 | 64-77 | 5 | 11,471 | Trevor Wilson | Ricky Bones | Ricky Bones | Trevor Wilson | | 571 | 621 | -50 |
| 1991-09-14 | vs SDN | 142 | L 1-3 | 64-78 | 5 | 19,439 | Gil Heredia | Andy Benes | Andy Benes | Gil Heredia | Mike Maddux | 572 | 624 | -52 |
| 1991-09-15 | vs SDN | 143 | W 7-2 | 65-78 | 5 | 14,049 | John Burkett | Dennis Rasmussen | John Burkett | Dennis Rasmussen | | 579 | 626 | -47 |
| 1991-09-16 | vs ATL | 144 | W 8-5 | 66-78 | 5 | 14,701 | Bryan Hickerson | Kent Mercker | Francisco Oliveras | Jim Clancy | Rod Beck | 587 | 631 | -44 |
| 1991-09-17 | vs ATL | 145 | W 3-2 | 67-78 | 5 | 8,481 | Buddy Black | Charlie Leibrandt | Buddy Black | Mike Stanton | Dave Righetti | 590 | 633 | -43 |
| 1991-09-18 | vs CIN | 146 | W 7-2 | 68-78 | 5 | 9,650 | Trevor Wilson | Jack Armstrong | Trevor Wilson | Jack Armstrong | | 597 | 635 | -38 |
| 1991-09-19 | vs CIN | 147 | W 4-1 | 69-78 | 5 | 9,458 | Gil Heredia | Randy Myers | Francisco Oliveras | Randy Myers | Dave Righetti | 601 | 636 | -35 |
| 1991-09-20 | @ SDN | 148 | L 5-10 | 69-79 | 5 | 12,409 | John Burkett | Dennis Rasmussen | John Costello | John Burkett | Jeremy Hernandez | 606 | 646 | -40 |
| 1991-09-21 | @ SDN | 149 | L 2-3 | 69-80 | 5 | 10,954 | Paul McClellan | Greg Harris | Greg Harris | Paul McClellan | Larry Andersen | 608 | 649 | -41 |
| 1991-09-22 | @ SDN | 150 | L 3-6 | 69-81 | 5 | 25,486 | Buddy Black | Jose Melendez | Rich Rodriguez | Francisco Oliveras | Craig Lefferts | 611 | 655 | -44 |
| 1991-09-23 | @ HOU | 151 | L 0-8 | 69-82 | 5 | 4,103 | Trevor Wilson | Pete Harnisch | Pete Harnisch | Trevor Wilson | Curt Schilling | 611 | 663 | -52 |
| 1991-09-24 | @ HOU | 152 | W 9-7 | 70-82 | 5 | 10,972 | Gil Heredia | Brian Williams | Rod Beck | Mark Portugal | | 620 | 670 | -50 |
| 1991-09-25 | @ HOU | 153 | W 2-1 | 71-82 | 5 | 7,322 | John Burkett | Darryl Kile | John Burkett | Darryl Kile | Jeff Brantley | 622 | 671 | -49 |
| 1991-09-27 | @ LAN | 154 | L 2-6 | 71-83 | 5 | 48,085 | Buddy Black | Tim Belcher | Tim Belcher | Buddy Black | | 624 | 677 | -53 |
| 1991-09-28 | @ LAN | 155 | W 4-1 | 72-83 | 5 | 44,258 | Trevor Wilson | Ramon Martinez | Trevor Wilson | Ramon Martinez | Don Robinson | 628 | 678 | -50 |
| 1991-09-29 | @ LAN | 156 | L 2-3 | 72-84 | 5 | 47,533 | Bryan Hickerson | Mike Morgan | Jim Gott | Dave Righetti | | 630 | 681 | -51 |
| 1991-09-30 | vs HOU | 157 | L 0-2 | 72-85 | 5 | 5,379 | Gil Heredia | Chris Gardner | Chris Gardner | Gil Heredia | Xavier Hernandez | 630 | 683 | -53 |
| 1991-10-01 | vs HOU | 158 | W 6-4 | 73-85 | 5 | 6,174 | John Burkett | Darryl Kile | John Burkett | Darryl Kile | Jeff Brantley | 636 | 687 | -51 |
| 1991-10-02 | vs HOU | 159 | L 5-7 | 73-86 | 5 | 5,823 | Paul McClellan | Ryan Bowen | Ryan Bowen | Paul McClellan | Al Osuna | 641 | 694 | -53 |
| 1991-10-04 | vs LAN | 160 | W 4-1 | 74-86 | 5 | 32,362 | Buddy Black | Ramon Martinez | Buddy Black | Ramon Martinez | Jeff Brantley | 645 | 695 | -50 |
| 1991-10-05 | vs LAN | 161 | W 4-0 | 75-86 | 4 | 42,712 | Trevor Wilson | Mike Morgan | Trevor Wilson | Mike Morgan | | 649 | 695 | -46 |
| 1991-10-06 | vs LAN | 162 | L 0-2 | 75-87 | 4 | 38,202 | Bryan Hickerson | Dennis Cook | Dennis Cook | Bryan Hickerson | Jay Howell | 649 | 697 | -48 |