| 1988-04-04 | @ CIN | 1 | L 4-5 | 0-1 | 6 | 55,438 | Joe Magrane | Mario Soto | Pat Perry | Bob Forsch | | 4 | 5 | -1 |
| 1988-04-07 | @ CIN | 2 | L 1-8 | 0-2 | 6 | 13,722 | Jose DeLeon | Danny Jackson | Danny Jackson | Jose DeLeon | | 5 | 13 | -8 |
| 1988-04-08 | vs PIT | 3 | L 3-4 | 0-3 | 6 | 51,647 | Danny Cox | Brian Fisher | Brian Fisher | Danny Cox | Jeff Robinson | 8 | 17 | -9 |
| 1988-04-09 | vs PIT | 4 | W 3-0 | 1-3 | 6 | 36,542 | Greg Mathews | Bob Walk | Greg Mathews | Bob Walk | Todd Worrell | 11 | 17 | -6 |
| 1988-04-10 | vs PIT | 5 | L 3-5 | 1-4 | 6 | 31,968 | Joe Magrane | John Smiley | Bob Kipper | Todd Worrell | Jim Gott | 14 | 22 | -8 |
| 1988-04-11 | vs CHN | 6 | L 1-6 | 1-5 | 6 | 32,275 | Bob Forsch | Greg Maddux | Greg Maddux | Bob Forsch | | 15 | 28 | -13 |
| 1988-04-12 | vs CHN | 7 | W 7-5 | 2-5 | 6 | 27,115 | Jose DeLeon | Al Nipper | Jose DeLeon | Drew Hall | Todd Worrell | 22 | 33 | -11 |
| 1988-04-13 | vs CHN | 8 | W 4-3 | 3-5 | 5 | 37,206 | Danny Cox | Jamie Moyer | Danny Cox | Les Lancaster | Todd Worrell | 26 | 36 | -10 |
| 1988-04-15 | @ NYN | 9 | L 0-3 | 3-6 | 6 | 33,094 | Greg Mathews | Dwight Gooden | Dwight Gooden | Greg Mathews | | 26 | 39 | -13 |
| 1988-04-16 | @ NYN | 10 | L 4-6 | 3-7 | 6 | 40,582 | Joe Magrane | Sid Fernandez | David Cone | Todd Worrell | Randy Myers | 30 | 45 | -15 |
| 1988-04-17 | @ NYN | 11 | L 2-3 | 3-8 | 6 | 48,760 | Jose DeLeon | Ron Darling | Roger McDowell | Steve Peters | | 32 | 48 | -16 |
| 1988-04-19 | @ PIT | 12 | L 0-3 | 3-9 | 6 | 5,048 | Danny Cox | Brian Fisher | Brian Fisher | Danny Cox | | 32 | 51 | -19 |
| 1988-04-20 | @ PIT | 13 | L 1-8 | 3-10 | 6 | 15,522 | Greg Mathews | Bob Walk | Bob Walk | Greg Mathews | | 33 | 59 | -26 |
| 1988-04-21 | @ PIT | 14 | W 9-3 | 4-10 | 6 | 6,833 | Randy O'Neal | John Smiley | Randy O'Neal | John Smiley | | 42 | 62 | -20 |
| 1988-04-22 | vs NYN | 15 | L 0-4 | 4-11 | 6 | 47,207 | Jose DeLeon | Ron Darling | Ron Darling | Jose DeLeon | | 42 | 66 | -24 |
| 1988-04-23 | vs NYN | 16 | L 9-12 | 4-12 | 6 | 45,110 | Bob Forsch | Sid Fernandez | Roger McDowell | Steve Peters | Randy Myers | 51 | 78 | -27 |
| 1988-04-24 | vs NYN | 17 | W 5-4 | 5-12 | 6 | 41,617 | Danny Cox | Bob Ojeda | Danny Cox | Jeff Innis | Todd Worrell | 56 | 82 | -26 |
| 1988-04-26 | @ SDN | 18 | L 0-1 | 5-13 | 6 | 15,553 | John Tudor | Eric Show | Eric Show | Randy O'Neal | | 56 | 83 | -27 |
| 1988-04-27 | @ SDN | 19 | W 2-1 | 6-13 | 6 | 14,417 | Greg Mathews | Jimmy Jones | Bob Forsch | Jimmy Jones | Todd Worrell | 58 | 84 | -26 |
| 1988-04-28 | @ SDN | 20 | W 6-4 | 7-13 | 6 | 21,075 | Jose DeLeon | Ed Whitson | Larry McWilliams | Greg Booker | Todd Worrell | 64 | 88 | -24 |
| 1988-04-29 | @ LAN | 21 | L 4-6 | 7-14 | 6 | 44,301 | Danny Cox | Orel Hershiser | Orel Hershiser | Danny Cox | Jay Howell | 68 | 94 | -26 |
| 1988-04-30 | @ LAN | 22 | W 5-2 | 8-14 | 6 | 47,425 | Randy O'Neal | Fernando Valenzuela | Randy O'Neal | Fernando Valenzuela | Larry McWilliams | 73 | 96 | -23 |
| 1988-05-01 | @ LAN | 23 | W 9-0 | 9-14 | 5 | 46,176 | John Tudor | Tim Leary | John Tudor | Tim Leary | Scott Terry | 82 | 96 | -14 |
| 1988-05-02 | @ SFN | 24 | W 5-1 | 10-14 | 5 | 18,398 | Jose DeLeon | Dave Dravecky | Jose DeLeon | Dave Dravecky | Todd Worrell | 87 | 97 | -10 |
| 1988-05-03 | @ SFN | 25 | L 0-2 | 10-15 | 5 | 18,157 | Larry McWilliams | Kelly Downs | Atlee Hammaker | Scott Terry | Craig Lefferts | 87 | 99 | -12 |
| 1988-05-04 | @ SFN | 26 | W 5-3 | 11-15 | 5 | 19,061 | Greg Mathews | Mike Krukow | Greg Mathews | Mike Krukow | Todd Worrell | 92 | 102 | -10 |
| 1988-05-06 | vs LAN | 27 | L 2-10 | 11-16 | 5 | 49,194 | Randy O'Neal | Fernando Valenzuela | Fernando Valenzuela | Randy O'Neal | | 94 | 112 | -18 |
| 1988-05-07 | vs LAN | 28 | W 2-1 | 12-16 | 5 | 46,159 | John Tudor | Tim Leary | Todd Worrell | Jesse Orosco | | 96 | 113 | -17 |
| 1988-05-08 | vs LAN | 29 | L 6-12 | 12-17 | 5 | 40,098 | Jose DeLeon | Don Sutton | Don Sutton | Jose DeLeon | | 102 | 125 | -23 |
| 1988-05-09 | vs SDN | 30 | W 7-1 | 13-17 | 5 | 27,289 | Larry McWilliams | Ed Whitson | Larry McWilliams | Ed Whitson | | 109 | 126 | -17 |
| 1988-05-10 | vs SDN | 31 | W 5-1 | 14-17 | 5 | 26,876 | Greg Mathews | Andy Hawkins | Bob Forsch | Andy Hawkins | Todd Worrell | 114 | 127 | -13 |
| 1988-05-11 | vs SFN | 32 | L 4-5 | 14-18 | 5 | 33,615 | Randy O'Neal | Mike LaCoss | Atlee Hammaker | Bob Forsch | | 118 | 132 | -14 |
| 1988-05-12 | vs SFN | 33 | W 13-12 | 15-18 | 5 | 39,707 | John Tudor | Rick Reuschel | Scott Terry | Craig Lefferts | Todd Worrell | 131 | 144 | -13 |
| 1988-05-13 | vs ATL | 34 | W 7-5 | 16-18 | 4 | 43,206 | Jose DeLeon | Pete Smith | Jose DeLeon | Pete Smith | Ken Dayley | 138 | 149 | -11 |
| 1988-05-14 | vs ATL | 35 | L 5-7 | 16-19 | 4 | 47,887 | Cris Carpenter | Zane Smith | Rick Mahler | Jose Oquendo | | 143 | 156 | -13 |
| 1988-05-15 | vs ATL | 36 | W 7-6 | 17-19 | 4 | 45,166 | Larry McWilliams | Tom Glavine | Todd Worrell | Bruce Sutter | | 150 | 162 | -12 |
| 1988-05-17 | @ CHN | 37 | W 3-0 | 18-19 | 4 | 21,762 | John Tudor | Greg Maddux | Scott Terry | Greg Maddux | Todd Worrell | 153 | 162 | -9 |
| 1988-05-18 | @ CHN | 38 | W 4-1 | 19-19 | 3 | 23,454 | Jose DeLeon | Jamie Moyer | Bob Forsch | Les Lancaster | Todd Worrell | 157 | 163 | -6 |
| 1988-05-19 | @ CHN | 39 | W 5-1 | 20-19 | 3 | 29,068 | Cris Carpenter | Al Nipper | Cris Carpenter | Al Nipper | | 162 | 164 | -2 |
| 1988-05-20 | vs HOU | 40 | L 3-5 | 20-20 | 3 | 48,787 | Larry McWilliams | Bob Knepper | Bob Knepper | Scott Terry | Dave Smith | 165 | 169 | -4 |
| 1988-05-21 | vs HOU | 41 | W 7-4 | 21-20 | 3 | 47,320 | Randy O'Neal | Danny Darwin | Bob Forsch | Joaquin Andujar | | 172 | 173 | -1 |
| 1988-05-22 | vs HOU | 42 | L 1-2 | 21-21 | 3 | 42,632 | John Tudor | Jim Deshaies | Juan Agosto | Ken Dayley | Larry Andersen | 173 | 175 | -2 |
| 1988-05-23 | vs CIN | 43 | L 3-8 | 21-22 | 3 | 30,237 | Jose DeLeon | Dennis Rasmussen | Dennis Rasmussen | Jose DeLeon | | 176 | 183 | -7 |
| 1988-05-24 | vs CIN | 44 | W 3-2 | 22-22 | 3 | 44,537 | Cris Carpenter | Ron Robinson | Ken Dayley | John Franco | | 179 | 185 | -6 |
| 1988-05-25 | vs CIN | 45 | W 6-0 | 23-22 | 3 | 40,168 | Larry McWilliams | Mario Soto | Larry McWilliams | Mario Soto | | 185 | 185 | 0 |
| 1988-05-27 | @ ATL | 46 | W 5-2 | 24-22 | 3 | 15,587 | Randy O'Neal | Zane Smith | Steve Peters | Jose Alvarez | Todd Worrell | 190 | 187 | 3 |
| 1988-05-28 | @ ATL | 47 | L 1-2 | 24-23 | 3 | 21,310 | John Tudor | Rick Mahler | Rick Mahler | John Tudor | Bruce Sutter | 191 | 189 | 2 |
| 1988-05-29 | @ ATL | 48 | W 3-1 | 25-23 | 3 | 34,673 | Jose DeLeon | Kevin Coffman | Jose DeLeon | Kevin Coffman | Ken Dayley | 194 | 190 | 4 |
| 1988-05-30 | @ HOU | 49 | L 4-5 | 25-24 | 3 | 26,000 | Cris Carpenter | Jim Deshaies | Jim Deshaies | Scott Terry | Dave Smith | 198 | 195 | 3 |
| 1988-05-31 | @ HOU | 50 | W 9-7 | 26-24 | 3 | 19,666 | Larry McWilliams | Bob Knepper | Larry McWilliams | Bob Knepper | Todd Worrell | 207 | 202 | 5 |
| 1988-06-01 | @ HOU | 51 | W 3-2 | 27-24 | 3 | 20,833 | Randy O'Neal | Danny Darwin | Steve Peters | Jeff Heathcock | Todd Worrell | 210 | 204 | 6 |
| 1988-06-02 | @ PHI | 52 | W 3-2 | 28-24 | 3 | 20,210 | John Tudor | Don Carman | John Costello | Danny Clay | | 213 | 206 | 7 |
| 1988-06-03 | @ PHI | 53 | W 5-4 | 29-24 | 3 | 26,836 | Jose DeLeon | Bruce Ruffin | Todd Worrell | Greg Harris | | 218 | 210 | 8 |
| 1988-06-04 | @ PHI | 54 | W 8-1 | 30-24 | 3 | 34,081 | Cris Carpenter | Shane Rawley | Cris Carpenter | Shane Rawley | | 226 | 211 | 15 |
| 1988-06-05 | @ PHI | 55 | L 3-6 | 30-25 | 3 | 43,429 | Randy O'Neal | David Palmer | David Palmer | Randy O'Neal | Steve Bedrosian | 229 | 217 | 12 |
| 1988-06-06 | vs NYN | 56 | L 2-6 | 30-26 | 3 | 44,199 | Larry McWilliams | Sid Fernandez | Sid Fernandez | Larry McWilliams | Randy Myers | 231 | 223 | 8 |
| 1988-06-07 | vs NYN | 57 | W 4-1 | 31-26 | 3 | 41,278 | John Tudor | David Cone | John Tudor | David Cone | Ken Dayley | 235 | 224 | 11 |
| 1988-06-08 | vs NYN | 58 | W 5-2 | 32-26 | 3 | 38,451 | Jose DeLeon | Bob Ojeda | Steve Peters | Roger McDowell | Todd Worrell | 240 | 226 | 14 |
| 1988-06-10 | vs CHN | 59 | L 3-7 | 32-27 | 3 | 49,306 | Cris Carpenter | Jeff Pico | Jeff Pico | Cris Carpenter | | 243 | 233 | 10 |
| 1988-06-11 | vs CHN | 60 | L 0-2 | 32-28 | 3 | 49,939 | Joe Magrane | Rick Sutcliffe | Rick Sutcliffe | Joe Magrane | Rich Gossage | 243 | 235 | 8 |
| 1988-06-12 | vs CHN | 61 | L 3-4 | 32-29 | 3 | 48,713 | John Tudor | Greg Maddux | Greg Maddux | John Tudor | Pat Perry | 246 | 239 | 7 |
| 1988-06-13 | @ NYN | 62 | L 1-2 | 32-30 | 3 | 37,311 | Larry McWilliams | David Cone | Randy Myers | Ken Dayley | | 247 | 241 | 6 |
| 1988-06-14 | @ NYN | 63 | L 0-5 | 32-31 | 3 | 38,042 | Jose DeLeon | Bob Ojeda | Bob Ojeda | Jose DeLeon | | 247 | 246 | 1 |
| 1988-06-15 | @ NYN | 64 | L 4-6 | 32-32 | 4 | 42,068 | Cris Carpenter | Ron Darling | Ron Darling | Cris Carpenter | Randy Myers | 251 | 252 | -1 |
| 1988-06-17 | @ PIT | 65 | W 7-3 | 33-32 | 4 | 30,267 | Joe Magrane | Mike Dunne | Joe Magrane | Mike Dunne | | 258 | 255 | 3 |
| 1988-06-18 | @ PIT | 66 | W 6-3 | 34-32 | 4 | 36,682 | John Tudor | Brian Fisher | John Tudor | Brian Fisher | Scott Terry | 264 | 258 | 6 |
| 1988-06-19 | @ PIT | 67 | L 2-3 | 34-33 | 4 | 27,656 | Larry McWilliams | Bob Walk | Bob Walk | Larry McWilliams | Jim Gott | 266 | 261 | 5 |
| 1988-06-20 | @ MON | 68 | L 2-3 | 34-34 | 4 | 13,232 | Jose DeLeon | Floyd Youmans | Floyd Youmans | Ken Dayley | Jeff Parrett | 268 | 264 | 4 |
| 1988-06-21 | @ MON | 69 | L 0-7 | 34-35 | 4 | 16,260 | Cris Carpenter | Pascual Perez | Pascual Perez | Cris Carpenter | | 268 | 271 | -3 |
| 1988-06-22 | @ MON | 70 | L 2-6 | 34-36 | 5 | 13,072 | Joe Magrane | Bryn Smith | Bryn Smith | Joe Magrane | Joe Hesketh | 270 | 277 | -7 |
| 1988-06-23 | vs PHI | 71 | W 2-0 | 35-36 | 4 | 36,176 | John Tudor | Shane Rawley | John Tudor | Shane Rawley | | 272 | 277 | -5 |
| 1988-06-24 | vs PHI | 72 | L 6-7 | 35-37 | 4 | 41,332 | Larry McWilliams | Don Carman | Bruce Ruffin | Todd Worrell | Steve Bedrosian | 278 | 284 | -6 |
| 1988-06-25 | vs PHI | 73 | W 4-1 | 36-37 | 4 | 44,214 | Jose DeLeon | Kevin Gross | Jose DeLeon | Kevin Gross | | 282 | 285 | -3 |
| 1988-06-26 | vs PHI | 74 | L 5-7 | 36-38 | 4 | 38,237 | Bob Forsch | David Palmer | Steve Bedrosian | Larry McWilliams | Bruce Ruffin | 287 | 292 | -5 |
| 1988-06-27 | vs MON | 75 | L 3-6 | 36-39 | 4 | 33,329 | Joe Magrane | Bryn Smith | Jeff Parrett | Steve Peters | Bob McClure | 290 | 298 | -8 |
| 1988-06-28 | vs MON | 76 | W 5-4 | 37-39 | 4 | 36,113 | John Tudor | John Dopson | Ken Dayley | Joe Hesketh | | 295 | 302 | -7 |
| 1988-06-29 | vs MON | 77 | L 2-3 | 37-40 | 4 | 37,921 | Danny Cox | Dennis Martinez | Jeff Parrett | Todd Worrell | | 297 | 305 | -8 |
| 1988-07-01 | @ SDN | 78 | L 1-5 | 37-41 | 5 | 16,440 | Jose DeLeon | Andy Hawkins | Andy Hawkins | Jose DeLeon | | 298 | 310 | -12 |
| 1988-07-02 | @ SDN | 79 | L 5-7 | 37-42 | 5 | 23,006 | Larry McWilliams | Dennis Rasmussen | Mark Grant | Ken Dayley | Mark Davis | 303 | 317 | -14 |
| 1988-07-03 | @ SDN | 80 | W 5-4 | 38-42 | 5 | 15,467 | Joe Magrane | Ed Whitson | Todd Worrell | Lance McCullers | | 308 | 321 | -13 |
| 1988-07-04 | @ LAN | 81 | L 3-5 | 38-43 | 5 | 44,855 | John Tudor | Bill Krueger | Alejandro Pena | John Tudor | Tim Belcher | 311 | 326 | -15 |
| 1988-07-05 | @ LAN | 82 | L 3-6 | 38-44 | 5 | 32,495 | Danny Cox | Orel Hershiser | Orel Hershiser | Danny Cox | Tim Belcher | 314 | 332 | -18 |
| 1988-07-06 | @ LAN | 83 | L 3-7 | 38-45 | 5 | 37,210 | Jose DeLeon | Fernando Valenzuela | Tim Crews | Todd Worrell | | 317 | 339 | -22 |
| 1988-07-08 | @ SFN | 84 | L 0-1 | 38-46 | 5 | 24,190 | Joe Magrane | Mike LaCoss | Mike LaCoss | Joe Magrane | | 317 | 340 | -23 |
| 1988-07-09 | @ SFN | 85 | L 2-21 | 38-47 | 5 | 34,666 | John Tudor | Kelly Downs | Kelly Downs | John Tudor | | 319 | 361 | -42 |
| 1988-07-10 | @ SFN | 86 | L 1-2 | 38-48 | 5 | 41,742 | Danny Cox | Terry Mulholland | Terry Mulholland | Danny Cox | | 320 | 363 | -43 |
| 1988-07-14 | vs SDN | 87 | L 1-3 | 38-49 | 5 | 28,938 | Jose DeLeon | Andy Hawkins | Andy Hawkins | Jose DeLeon | | 321 | 366 | -45 |
| 1988-07-15 | vs SDN | 88 | L 3-7 | 38-50 | 5 | 34,414 | John Tudor | Dennis Rasmussen | Mark Davis | Todd Worrell | | 324 | 373 | -49 |
| 1988-07-16 | vs SDN | 89 | W 3-2 | 39-50 | 5 | 43,338 | Danny Cox | Ed Whitson | John Costello | Mark Davis | | 327 | 375 | -48 |
| 1988-07-17 | vs SDN | 90 | L 1-3 | 39-51 | 6 | 27,926 | Joe Magrane | Eric Show | Eric Show | Joe Magrane | | 328 | 378 | -50 |
| 1988-07-18 | vs LAN | 91 | L 0-1 | 39-52 | 6 | 29,358 | Bob Forsch | Tim Leary | Tim Leary | Todd Worrell | | 328 | 379 | -51 |
| 1988-07-19 | vs LAN | 92 | W 3-2 | 40-52 | 6 | 34,606 | Jose DeLeon | William Brennan | Jose DeLeon | William Brennan | Todd Worrell | 331 | 381 | -50 |
| 1988-07-20 | vs LAN | 93 | W 8-7 | 41-52 | 6 | 31,845 | John Tudor | Fernando Valenzuela | John Costello | Fernando Valenzuela | Todd Worrell | 339 | 388 | -49 |
| 1988-07-21 | vs SFN | 94 | W 6-4 | 42-52 | 5 | 35,983 | Danny Cox | Terry Mulholland | Danny Cox | Joe Price | Todd Worrell | 345 | 392 | -47 |
| 1988-07-22 | vs SFN | 95 | W 4-2 | 43-52 | 5 | 44,472 | Joe Magrane | Don Robinson | Dan Quisenberry | Craig Lefferts | | 349 | 394 | -45 |
| 1988-07-23 | vs SFN | 96 | L 5-6 | 43-53 | 5 | 42,072 | Bob Forsch | Atlee Hammaker | Scott Garrelts | Todd Worrell | | 354 | 400 | -46 |
| 1988-07-24 | vs SFN | 97 | L 0-5 | 43-54 | 5 | 39,183 | Jose DeLeon | Rick Reuschel | Rick Reuschel | Jose DeLeon | | 354 | 405 | -51 |
| 1988-07-25 | vs PIT | 98 | W 5-1 | 44-54 | 5 | 30,763 | John Tudor | Bob Walk | John Tudor | Bob Walk | | 359 | 406 | -47 |
| 1988-07-26 | vs PIT | 99 | L 1-2 | 44-55 | 5 | 32,735 | Danny Cox | Doug Drabek | Doug Drabek | Danny Cox | Jim Gott | 360 | 408 | -48 |
| 1988-07-27 | vs PIT | 100 | L 2-3 | 44-56 | 5 | 31,618 | Joe Magrane | Mike Dunne | Jeff Robinson | Ken Dayley | Jim Gott | 362 | 411 | -49 |
| 1988-07-28 | @ MON | 101 | L 3-4 | 44-57 | 5 | 20,751 | Bob Forsch | Bryn Smith | Tim Burke | Larry McWilliams | | 365 | 415 | -50 |
| 1988-07-29 | @ MON | 102 | W 7-5 | 45-57 | 5 | 32,198 | Jose DeLeon | Pascual Perez | Jose DeLeon | Pascual Perez | Todd Worrell | 372 | 420 | -48 |
| 1988-07-30 | @ MON | 103 | L 1-2 | 45-58 | 5 | 24,719 | John Tudor | John Dopson | Joe Hesketh | Todd Worrell | | 373 | 422 | -49 |
| 1988-07-31 | @ MON | 104 | L 0-2 | 45-59 | 6 | 35,016 | Danny Cox | Dennis Martinez | Dennis Martinez | Danny Cox | | 373 | 424 | -51 |
| 1988-08-02 | vs PHI | 105 | L 0-2 | 45-60 | 6 | 27,744 | Joe Magrane | David Palmer | David Palmer | Joe Magrane | | 373 | 426 | -53 |
| 1988-08-03 | vs PHI | 106 | W 4-2 | 46-60 | 6 | 23,277 | Bob Forsch | Kevin Gross | Bob Forsch | Kevin Gross | Scott Terry | 377 | 428 | -51 |
| 1988-08-04 | vs PHI | 107 | W 9-2 | 47-60 | 5 | 23,955 | Jose DeLeon | Shane Rawley | Jose DeLeon | Shane Rawley | | 386 | 430 | -44 |
| 1988-08-05 | vs MON | 108 | L 1-3 | 47-61 | 6 | 45,023 | John Tudor | Dennis Martinez | Dennis Martinez | John Tudor | | 387 | 433 | -46 |
| 1988-08-06 | vs MON | 109 | L 4-5 | 47-62 | 6 | 36,338 | Danny Cox | Brian Holman | Brian Holman | Danny Cox | Tim Burke | 391 | 438 | -47 |
| 1988-08-07 | vs MON | 110 | L 5-11 | 47-63 | 6 | 27,748 | Joe Magrane | Bryn Smith | Bryn Smith | Joe Magrane | Tim Barrett | 396 | 449 | -53 |
| 1988-08-08 | vs MON | 111 | W 4-2 | 48-63 | 6 | 28,916 | Bob Forsch | Pascual Perez | Bob Forsch | Pascual Perez | Todd Worrell | 400 | 451 | -51 |
| 1988-08-09 | @ PHI | 112 | W 7-3 | 49-63 | 6 | 25,533 | Jose DeLeon | Marvin Freeman | Dan Quisenberry | Steve Bedrosian | | 407 | 454 | -47 |
| 1988-08-10 | @ PHI | 113 | W 1-0 | 50-63 | 5 | 24,837 | John Tudor | Don Carman | John Tudor | Don Carman | Todd Worrell | 408 | 454 | -46 |
| 1988-08-11 | @ PHI | 114 | L 0-1 | 50-64 | 6 | 25,607 | Scott Terry | Mike Maddux | Steve Bedrosian | John Costello | | 408 | 455 | -47 |
| 1988-08-12 | @ CHN | 115 | W 4-0 | 51-64 | 6 | 31,596 | Joe Magrane | Rick Sutcliffe | Joe Magrane | Rick Sutcliffe | | 412 | 455 | -43 |
| 1988-08-13 | @ CHN | 116 | L 1-5 | 51-65 | 6 | 34,696 | Bob Forsch | Jamie Moyer | Jamie Moyer | Bob Forsch | | 413 | 460 | -47 |
| 1988-08-14 | @ CHN | 117 | L 3-8 | 51-66 | 6 | 32,016 | Jose DeLeon | Mike Bielecki | Mike Bielecki | Ken Dayley | Les Lancaster | 416 | 468 | -52 |
| 1988-08-16 | vs HOU | 118 | W 3-0 | 52-66 | 5 | 26,044 | Scott Terry | Jim Deshaies | Scott Terry | Jim Deshaies | Ken Dayley | 419 | 468 | -49 |
| 1988-08-17 | vs HOU | 119 | L 0-1 | 52-67 | 5 | 25,343 | Joe Magrane | Dave Meads | Dave Meads | Joe Magrane | Dave Smith | 419 | 469 | -50 |
| 1988-08-18 | vs HOU | 120 | W 2-1 | 53-67 | 5 | 27,355 | Bob Forsch | Mike Scott | Bob Forsch | Mike Scott | Todd Worrell | 421 | 470 | -49 |
| 1988-08-19 | vs CIN | 121 | W 10-4 | 54-67 | 5 | 36,322 | Jose DeLeon | Norm Charlton | John Costello | Norm Charlton | Todd Worrell | 431 | 474 | -43 |
| 1988-08-20 | vs CIN | 122 | L 2-6 | 54-68 | 5 | 36,703 | Greg Mathews | Tom Browning | Tom Browning | Greg Mathews | Frank Williams | 433 | 480 | -47 |
| 1988-08-21 | vs CIN | 123 | W 7-1 | 55-68 | 5 | 34,129 | Scott Terry | Tim Birtsas | Scott Terry | Tim Birtsas | | 440 | 481 | -41 |
| 1988-08-22 | vs ATL | 124 | L 3-5 | 55-69 | 5 | 23,635 | Joe Magrane | Tom Glavine | Tom Glavine | Joe Magrane | Jose Alvarez | 443 | 486 | -43 |
| 1988-08-23 | vs ATL | 125 | W 7-0 | 56-69 | 5 | 23,806 | Bob Forsch | John Smoltz | Bob Forsch | John Smoltz | | 450 | 486 | -36 |
| 1988-08-24 | vs ATL | 126 | W 5-3 | 57-69 | 5 | 24,997 | Jose DeLeon | Rick Mahler | Todd Worrell | Bruce Sutter | | 455 | 489 | -34 |
| 1988-08-25 | @ CIN | 127 | L 1-4 | 57-70 | 5 | 15,380 | Greg Mathews | Keith Brown | Keith Brown | Greg Mathews | John Franco | 456 | 493 | -37 |
| 1988-08-26 | @ CIN | 128 | W 4-2 | 58-70 | 5 | 32,170 | Scott Terry | Danny Jackson | Scott Terry | Danny Jackson | Todd Worrell | 460 | 495 | -35 |
| 1988-08-27 | @ CIN | 129 | L 2-3 | 58-71 | 5 | 35,894 | Joe Magrane | Norm Charlton | John Franco | Larry McWilliams | | 462 | 498 | -36 |
| 1988-08-28 | @ CIN | 130 | W 5-3 | 59-71 | 5 | 28,256 | Bob Forsch | Tom Browning | Bob Forsch | Tom Browning | Todd Worrell | 467 | 501 | -34 |
| 1988-08-29 | @ ATL | 131 | W 3-2 | 60-71 | 5 | 6,668 | Jose DeLeon | Rick Mahler | Jose DeLeon | Rick Mahler | John Costello | 470 | 503 | -33 |
| 1988-08-30 | @ ATL | 132 | W 9-1 | 61-71 | 5 | 6,278 | Greg Mathews | German Jimenez | Greg Mathews | German Jimenez | | 479 | 504 | -25 |
| 1988-08-31 | @ ATL | 133 | W 6-4 | 62-71 | 5 | 6,358 | Scott Terry | Pete Smith | Scott Terry | Pete Smith | Todd Worrell | 485 | 508 | -23 |
| 1988-09-02 | @ HOU | 134 | W 2-0 | 63-71 | 5 | 16,054 | Joe Magrane | Mike Scott | Joe Magrane | Mike Scott | | 487 | 508 | -21 |
| 1988-09-03 | @ HOU | 135 | L 1-10 | 63-72 | 5 | 24,463 | Larry McWilliams | Nolan Ryan | Nolan Ryan | Larry McWilliams | | 488 | 518 | -30 |
| 1988-09-04 | @ HOU | 136 | L 3-4 | 63-73 | 5 | 20,309 | Greg Mathews | Bob Knepper | Bob Knepper | Greg Mathews | Dave Smith | 491 | 522 | -31 |
| 1988-09-05 | vs MON | 137 | W 6-2 | 64-73 | 5 | 25,782 | Scott Terry | John Dopson | Scott Terry | John Dopson | | 497 | 524 | -27 |
| 1988-09-06 | vs MON | 138 | W 1-0 | 65-73 | 5 | 18,902 | Jose DeLeon | Dennis Martinez | Jose DeLeon | Dennis Martinez | | 498 | 524 | -26 |
| 1988-09-07 | vs PHI | 139 | W 5-0 | 66-73 | 5 | 23,535 | Joe Magrane | Don Carman | Joe Magrane | Don Carman | | 503 | 524 | -21 |
| 1988-09-08 | vs PHI | 140 | W 1-0 | 67-73 | 5 | 19,211 | Larry McWilliams | Kevin Gross | Larry McWilliams | Kevin Gross | Todd Worrell | 504 | 524 | -20 |
| 1988-09-09 | vs CHN | 141 | W 6-2 | 68-73 | 5 | 38,991 | Greg Mathews | Calvin Schiraldi | Greg Mathews | Calvin Schiraldi | Todd Worrell | 510 | 526 | -16 |
| 1988-09-10 | vs CHN | 142 | W 9-3 | 69-73 | 5 | 41,151 | Scott Terry | Rick Sutcliffe | Scott Terry | Rick Sutcliffe | | 519 | 529 | -10 |
| 1988-09-11 | vs CHN | 143 | W 3-2 | 70-73 | 4 | 39,440 | Jose DeLeon | Mike Harkey | Jose DeLeon | Mike Harkey | Ken Dayley | 522 | 531 | -9 |
| 1988-09-12 | @ MON | 144 | L 2-14 | 70-74 | 4 | 7,632 | Joe Magrane | Bryn Smith | Bryn Smith | Joe Magrane | Mike Smith | 524 | 545 | -21 |
| 1988-09-13 | @ MON | 145 | L 1-7 | 70-75 | 5 | 8,623 | Larry McWilliams | Pascual Perez | Pascual Perez | Larry McWilliams | | 525 | 552 | -27 |
| 1988-09-14 | @ PHI | 146 | L 2-9 | 70-76 | 5 | 13,829 | Greg Mathews | Bob Sebra | Bob Sebra | Greg Mathews | | 527 | 561 | -34 |
| 1988-09-15 | @ PHI | 147 | W 3-1 | 71-76 | 4 | 10,434 | Scott Terry | Shane Rawley | Scott Terry | Shane Rawley | Todd Worrell | 530 | 562 | -32 |
| 1988-09-16 | @ CHN | 148 | W 3-0 | 72-76 | 4 | 15,771 | Jose DeLeon | Mike Harkey | Jose DeLeon | Mike Harkey | Todd Worrell | 533 | 562 | -29 |
| 1988-09-17 | @ CHN | 149 | L 4-6 | 72-77 | 4 | 30,243 | Joe Magrane | Jamie Moyer | Jeff Pico | John Costello | | 537 | 568 | -31 |
| 1988-09-18 | @ CHN | 150 | W 5-4 | 73-77 | 4 | 25,090 | Larry McWilliams | Greg Maddux | Larry McWilliams | Greg Maddux | Todd Worrell | 542 | 572 | -30 |
| 1988-09-19 | vs PIT | 151 | L 4-5 | 73-78 | 4 | 19,683 | Greg Mathews | Mike Dunne | Jeff Robinson | Ken Dayley | Jim Gott | 546 | 577 | -31 |
| 1988-09-20 | vs PIT | 152 | L 1-5 | 73-79 | 4 | 27,441 | Scott Terry | Dave LaPoint | Scott Medvin | Scott Terry | Jim Gott | 547 | 582 | -35 |
| 1988-09-21 | vs PIT | 153 | L 0-5 | 73-80 | 4 | 28,350 | Jose DeLeon | John Smiley | John Smiley | Jose DeLeon | | 547 | 587 | -40 |
| 1988-09-23 | vs NYN | 154 | W 2-1 | 74-80 | 4 | 33,290 | Joe Magrane | Dwight Gooden | John Costello | Dwight Gooden | | 549 | 588 | -39 |
| 1988-09-24 | vs NYN | 155 | L 1-14 | 74-81 | 5 | 35,670 | Larry McWilliams | David West | David West | Larry McWilliams | | 550 | 602 | -52 |
| 1988-09-25 | vs NYN | 156 | L 7-9 | 74-82 | 5 | 39,284 | Scott Terry | David Cone | David Cone | Scott Terry | Randy Myers | 557 | 611 | -54 |
| 1988-09-26 | @ PIT | 157 | W 7-1 | 75-82 | 4 | 9,044 | Jose DeLeon | Dave LaPoint | Jose DeLeon | Dave LaPoint | | 564 | 612 | -48 |
| 1988-09-27 | @ PIT | 158 | L 2-3 | 75-83 | 5 | 8,994 | Ken Hill | John Smiley | John Smiley | Ken Hill | Jim Gott | 566 | 615 | -49 |
| 1988-09-28 | @ PIT | 159 | W 2-1 | 76-83 | 5 | 21,004 | Joe Magrane | Doug Drabek | Joe Magrane | Doug Drabek | | 568 | 616 | -48 |
| 1988-09-30 | @ NYN | 160 | L 2-4 | 76-84 | 4 | 38,270 | Scott Terry | David Cone | David Cone | Scott Terry | | 570 | 620 | -50 |
| 1988-10-01 | @ NYN | 161 | L 3-6 | 76-85 | 5 | 36,528 | Jose DeLeon | Sid Fernandez | Sid Fernandez | Jose DeLeon | Bob McClure | 573 | 626 | -53 |
| 1988-10-02 | @ NYN | 162 | L 5-7 | 76-86 | 5 | 42,099 | Larry McWilliams | Ron Darling | Ron Darling | Larry McWilliams | Randy Myers | 578 | 633 | -55 |