| 1988-04-04 | vs NYN | 1 | L 6-10 | 0-1 | 3 | 55,413 | Dennis Martinez | Dwight Gooden | Dwight Gooden | Dennis Martinez | Randy Myers | 6 | 10 | -4 |
| 1988-04-06 | vs NYN | 2 | W 5-1 | 1-1 | 2 | 11,112 | Pascual Perez | Ron Darling | Pascual Perez | Ron Darling | | 11 | 11 | 0 |
| 1988-04-07 | vs NYN | 3 | L 5-8 | 1-2 | 5 | 10,193 | Neal Heaton | Bob Ojeda | Bob Ojeda | Neal Heaton | | 16 | 19 | -3 |
| 1988-04-08 | vs CHN | 4 | L 4-6 | 1-3 | 5 | 12,133 | Floyd Youmans | Jamie Moyer | Jamie Moyer | Floyd Youmans | Rich Gossage | 20 | 25 | -5 |
| 1988-04-09 | vs CHN | 5 | W 10-6 | 2-3 | 4 | 11,806 | Dennis Martinez | Calvin Schiraldi | Dennis Martinez | Calvin Schiraldi | | 30 | 31 | -1 |
| 1988-04-10 | vs CHN | 6 | L 7-10 | 2-4 | 5 | 15,704 | Bryn Smith | Rick Sutcliffe | Rich Gossage | Bob McClure | Les Lancaster | 37 | 41 | -4 |
| 1988-04-12 | @ NYN | 7 | L 0-3 | 2-5 | 5 | 48,719 | Pascual Perez | Ron Darling | Ron Darling | Pascual Perez | | 37 | 44 | -7 |
| 1988-04-14 | @ NYN | 8 | L 0-1 | 2-6 | 6 | 19,612 | Dennis Martinez | Bob Ojeda | Bob Ojeda | Dennis Martinez | | 37 | 45 | -8 |
| 1988-04-15 | vs PHI | 9 | W 6-4 | 3-6 | 4 | 11,292 | Floyd Youmans | Shane Rawley | Andy McGaffigan | Todd Frohwirth | Tim Burke | 43 | 49 | -6 |
| 1988-04-16 | vs PHI | 10 | W 2-1 | 4-6 | 4 | 13,664 | Bryn Smith | Kevin Gross | Tim Burke | Kent Tekulve | | 45 | 50 | -5 |
| 1988-04-17 | vs PHI | 11 | W 5-2 | 5-6 | 4 | 16,597 | Pascual Perez | David Palmer | Pascual Perez | Bill Dawley | Andy McGaffigan | 50 | 52 | -2 |
| 1988-04-19 | @ CHN | 12 | W 9-1 | 6-6 | 4 | 7,293 | Dennis Martinez | Jamie Moyer | Dennis Martinez | Jamie Moyer | | 59 | 53 | 6 |
| 1988-04-20 | @ CHN | 13 | W 5-1 | 7-6 | 3 | 5,699 | Floyd Youmans | Rick Sutcliffe | Jeff Parrett | Rick Sutcliffe | Tim Burke | 64 | 54 | 10 |
| 1988-04-21 | @ CHN | 14 | L 2-6 | 7-7 | 4 | 6,625 | Bryn Smith | Greg Maddux | Greg Maddux | Bryn Smith | | 66 | 60 | 6 |
| 1988-04-22 | @ PHI | 15 | L 0-2 | 7-8 | 4 | 22,113 | Pascual Perez | Kevin Gross | Kevin Gross | Pascual Perez | | 66 | 62 | 4 |
| 1988-04-23 | @ PHI | 16 | L 3-3 | 7-9 | 4 | 23,394 | John Dopson | Bruce Ruffin | | | | 69 | 65 | 4 |
| 1988-04-24 | @ PHI | 17 | W 3-1 | 8-9 | 3 | 47,917 | Dennis Martinez | Don Carman | Dennis Martinez | Don Carman | Tim Burke | 72 | 66 | 6 |
| 1988-04-26 | vs CIN | 18 | L 2-5 | 8-10 | 4 | 11,150 | Floyd Youmans | Ron Robinson | Ron Robinson | Floyd Youmans | John Franco | 74 | 71 | 3 |
| 1988-04-27 | vs CIN | 19 | W 1-0 | 9-10 | 3 | 12,197 | Pascual Perez | Mario Soto | Pascual Perez | Mario Soto | | 75 | 71 | 4 |
| 1988-04-29 | @ HOU | 20 | L 4-6 | 9-11 | 3 | 34,331 | Dennis Martinez | Danny Darwin | Juan Agosto | Tim Burke | Dave Smith | 79 | 77 | 2 |
| 1988-04-30 | @ HOU | 21 | L 0-3 | 9-12 | 4 | 30,384 | Bryn Smith | Jim Deshaies | Jim Deshaies | Bryn Smith | Dave Smith | 79 | 80 | -1 |
| 1988-05-01 | @ HOU | 22 | W 7-3 | 10-12 | 3 | 26,231 | Neal Heaton | Mike Scott | Jeff Parrett | Jeff Heathcock | | 86 | 83 | 3 |
| 1988-05-02 | @ CIN | 23 | L 2-3 | 10-13 | 4 | 15,107 | Pascual Perez | Ron Robinson | Ron Robinson | Pascual Perez | John Franco | 88 | 86 | 2 |
| 1988-05-03 | @ CIN | 24 | W 4-3 | 11-13 | 4 | 16,910 | Floyd Youmans | Mario Soto | Joe Hesketh | Rob Murphy | Tim Burke | 92 | 89 | 3 |
| 1988-05-04 | vs ATL | 25 | L 5-7 | 11-14 | 4 | 10,762 | Dennis Martinez | Kevin Coffman | Kevin Coffman | Dennis Martinez | Bruce Sutter | 97 | 96 | 1 |
| 1988-05-05 | vs ATL | 26 | W 4-1 | 12-14 | 4 | 10,686 | Bryn Smith | Rick Mahler | Bryn Smith | Rick Mahler | Jeff Parrett | 101 | 97 | 4 |
| 1988-05-06 | vs HOU | 27 | W 6-5 | 13-14 | 4 | 16,572 | Neal Heaton | Mike Scott | Bob McClure | Ernie Camacho | | 107 | 102 | 5 |
| 1988-05-07 | vs HOU | 28 | W 4-3 | 14-14 | 4 | 12,661 | Pascual Perez | Nolan Ryan | Jeff Parrett | Jeff Heathcock | | 111 | 105 | 6 |
| 1988-05-08 | vs HOU | 29 | L 2-7 | 14-15 | 4 | 14,873 | Floyd Youmans | Bob Knepper | Bob Knepper | Floyd Youmans | | 113 | 112 | 1 |
| 1988-05-09 | @ ATL | 30 | L 8-9 | 14-16 | 4 | 4,274 | Dennis Martinez | Rick Mahler | Rick Mahler | Dennis Martinez | Bruce Sutter | 121 | 121 | 0 |
| 1988-05-10 | @ ATL | 31 | W 6-1 | 15-16 | 4 | 3,679 | Bryn Smith | Tom Glavine | Bryn Smith | Tom Glavine | | 127 | 122 | 5 |
| 1988-05-11 | @ ATL | 32 | L 2-3 | 15-17 | 4 | 4,852 | Neal Heaton | Kevin Coffman | Kevin Coffman | Neal Heaton | Bruce Sutter | 129 | 125 | 4 |
| 1988-05-13 | @ SDN | 33 | L 1-7 | 15-18 | 5 | 13,707 | John Dopson | Jimmy Jones | Jimmy Jones | John Dopson | | 130 | 132 | -2 |
| 1988-05-14 | @ SDN | 34 | L 2-3 | 15-19 | 5 | 43,811 | Dennis Martinez | Ed Whitson | Ed Whitson | Dennis Martinez | Lance McCullers | 132 | 135 | -3 |
| 1988-05-15 | @ SDN | 35 | L 1-2 | 15-20 | 5 | 21,478 | Bryn Smith | Andy Hawkins | Andy Hawkins | Jeff Parrett | Mark Davis | 133 | 137 | -4 |
| 1988-05-17 | @ LAN | 36 | W 6-5 | 16-20 | 5 | 34,309 | Neal Heaton | Fernando Valenzuela | Neal Heaton | Fernando Valenzuela | Tim Burke | 139 | 142 | -3 |
| 1988-05-18 | @ LAN | 37 | W 3-0 | 17-20 | 5 | 27,775 | John Dopson | Orel Hershiser | John Dopson | Orel Hershiser | Tim Burke | 142 | 142 | 0 |
| 1988-05-19 | @ LAN | 38 | L 0-2 | 17-21 | 5 | 25,283 | Dennis Martinez | Tim Leary | Tim Leary | Dennis Martinez | | 142 | 144 | -2 |
| 1988-05-20 | @ SFN | 39 | L 2-11 | 17-22 | 5 | 15,510 | Bryn Smith | Mike LaCoss | Mike LaCoss | Bryn Smith | | 144 | 155 | -11 |
| 1988-05-21 | @ SFN | 40 | W 6-0 | 18-22 | 5 | 31,510 | Floyd Youmans | Rick Reuschel | Floyd Youmans | Rick Reuschel | | 150 | 155 | -5 |
| 1988-05-22 | @ SFN | 41 | L 2-7 | 18-23 | 5 | 28,831 | Neal Heaton | Kelly Downs | Kelly Downs | Neal Heaton | | 152 | 162 | -10 |
| 1988-05-24 | vs SDN | 42 | W 7-6 | 19-23 | 5 | 14,234 | John Dopson | Jimmy Jones | Andy McGaffigan | Candy Sierra | | 159 | 168 | -9 |
| 1988-05-25 | vs SDN | 43 | W 6-2 | 20-23 | 5 | 10,586 | Dennis Martinez | Ed Whitson | Dennis Martinez | Ed Whitson | | 165 | 170 | -5 |
| 1988-05-26 | vs SDN | 44 | W 6-2 | 21-23 | 5 | 9,554 | Bryn Smith | Andy Hawkins | Bryn Smith | Andy Hawkins | Jeff Parrett | 171 | 172 | -1 |
| 1988-05-27 | vs LAN | 45 | L 2-5 | 21-24 | 5 | 18,113 | Floyd Youmans | Tim Belcher | Jesse Orosco | Bob McClure | Alejandro Pena | 173 | 177 | -4 |
| 1988-05-28 | vs LAN | 46 | W 3-2 | 22-24 | 5 | 15,320 | Neal Heaton | Fernando Valenzuela | Jeff Parrett | Jay Howell | | 176 | 179 | -3 |
| 1988-05-29 | vs LAN | 47 | L 1-2 | 22-25 | 5 | 35,311 | John Dopson | Orel Hershiser | Orel Hershiser | John Dopson | | 177 | 181 | -4 |
| 1988-05-30 | vs SFN | 48 | W 3-2 | 23-25 | 5 | 10,762 | Dennis Martinez | Mike LaCoss | Andy McGaffigan | Scott Garrelts | | 180 | 183 | -3 |
| 1988-05-31 | vs SFN | 49 | L 2-9 | 23-26 | 5 | 11,902 | Bryn Smith | Rick Reuschel | Rick Reuschel | Bryn Smith | | 182 | 192 | -10 |
| 1988-06-01 | vs SFN | 50 | L 1-2 | 23-27 | 5 | 12,074 | Floyd Youmans | Kelly Downs | Kelly Downs | Floyd Youmans | Craig Lefferts | 183 | 194 | -11 |
| 1988-06-02 | @ PIT | 51 | W 7-3 | 24-27 | 5 | 11,070 | Neal Heaton | Bob Walk | Neal Heaton | Bob Walk | Joe Hesketh | 190 | 197 | -7 |
| 1988-06-03 | @ PIT | 52 | L 1-2 | 24-28 | 5 | 19,162 | John Dopson | John Smiley | John Smiley | John Dopson | | 191 | 199 | -8 |
| 1988-06-04 | @ PIT | 53 | W 7-3 | 25-28 | 5 | 30,669 | Dennis Martinez | Doug Drabek | Dennis Martinez | Doug Drabek | Bob McClure | 198 | 202 | -4 |
| 1988-06-05 | @ PIT | 54 | W 3-2 | 26-28 | 5 | 36,305 | Bryn Smith | Mike Dunne | Bryn Smith | Mike Dunne | Jeff Parrett | 201 | 204 | -3 |
| 1988-06-06 | vs PHI | 55 | L 4-5 | 26-29 | 5 | 12,127 | Floyd Youmans | Kevin Gross | Kevin Gross | Floyd Youmans | Steve Bedrosian | 205 | 209 | -4 |
| 1988-06-07 | vs PHI | 56 | L 5-10 | 26-30 | 5 | 11,556 | Neal Heaton | Don Carman | Greg Harris | Neal Heaton | Kent Tekulve | 210 | 219 | -9 |
| 1988-06-08 | vs PHI | 57 | W 5-4 | 27-30 | 5 | 10,214 | John Dopson | Bruce Ruffin | Jeff Parrett | Steve Bedrosian | | 215 | 223 | -8 |
| 1988-06-10 | vs NYN | 58 | W 5-2 | 28-30 | 5 | 28,697 | Dennis Martinez | Ron Darling | Dennis Martinez | Ron Darling | Jeff Parrett | 220 | 225 | -5 |
| 1988-06-11 | vs NYN | 59 | W 6-4 | 29-30 | 5 | 31,576 | Floyd Youmans | Dwight Gooden | Floyd Youmans | Dwight Gooden | Andy McGaffigan | 226 | 229 | -3 |
| 1988-06-12 | vs NYN | 60 | W 4-3 | 30-30 | 5 | 32,245 | Bryn Smith | Sid Fernandez | Tim Burke | Terry Leach | | 230 | 232 | -2 |
| 1988-06-13 | @ PHI | 61 | L 2-5 | 30-31 | 5 | 20,544 | Neal Heaton | Shane Rawley | Shane Rawley | Neal Heaton | | 232 | 237 | -5 |
| 1988-06-14 | @ PHI | 62 | W 9-0 | 31-32 | 5 | 0 | Dennis Martinez | Bruce Ruffin | Dennis Martinez | Bruce Ruffin | | 241 | 237 | 4 |
| 1988-06-14 | @ PHI | 63 | L 2-4 | 31-32 | 5 | 24,082 | John Dopson | Don Carman | Don Carman | John Dopson | Steve Bedrosian | 243 | 241 | 2 |
| 1988-06-15 | @ PHI | 64 | L 2-6 | 31-33 | 5 | 23,553 | Floyd Youmans | David Palmer | David Palmer | Floyd Youmans | Steve Bedrosian | 245 | 247 | -2 |
| 1988-06-17 | @ CHN | 65 | L 3-7 | 31-34 | 5 | 33,041 | Bryn Smith | Rick Sutcliffe | Rick Sutcliffe | Bryn Smith | Les Lancaster | 248 | 254 | -6 |
| 1988-06-18 | @ CHN | 66 | L 0-3 | 31-35 | 5 | 33,197 | John Dopson | Greg Maddux | Greg Maddux | John Dopson | | 248 | 257 | -9 |
| 1988-06-19 | @ CHN | 67 | L 3-9 | 31-36 | 5 | 32,300 | Dennis Martinez | Calvin Schiraldi | Calvin Schiraldi | Dennis Martinez | | 251 | 266 | -15 |
| 1988-06-20 | vs SLN | 68 | W 3-2 | 32-36 | 5 | 13,232 | Floyd Youmans | Jose DeLeon | Floyd Youmans | Ken Dayley | Jeff Parrett | 254 | 268 | -14 |
| 1988-06-21 | vs SLN | 69 | W 7-0 | 33-36 | 5 | 16,260 | Pascual Perez | Cris Carpenter | Pascual Perez | Cris Carpenter | | 261 | 268 | -7 |
| 1988-06-22 | vs SLN | 70 | W 6-2 | 34-36 | 4 | 13,072 | Bryn Smith | Joe Magrane | Bryn Smith | Joe Magrane | Joe Hesketh | 267 | 270 | -3 |
| 1988-06-23 | vs PIT | 71 | L 4-6 | 34-37 | 5 | 14,839 | John Dopson | Brian Fisher | Jeff Robinson | Jeff Parrett | Jim Gott | 271 | 276 | -5 |
| 1988-06-24 | vs PIT | 72 | L 3-5 | 34-38 | 5 | 15,781 | Dennis Martinez | Bob Walk | Jim Gott | Bob McClure | Barry Jones | 274 | 281 | -7 |
| 1988-06-25 | vs PIT | 73 | L 1-5 | 34-39 | 5 | 17,777 | Brian Holman | John Smiley | John Smiley | Brian Holman | | 275 | 286 | -11 |
| 1988-06-26 | vs PIT | 74 | L 0-3 | 34-40 | 6 | 26,593 | Pascual Perez | Doug Drabek | Jeff Robinson | Tim Burke | | 275 | 289 | -14 |
| 1988-06-27 | @ SLN | 75 | W 6-3 | 35-40 | 5 | 33,329 | Bryn Smith | Joe Magrane | Jeff Parrett | Steve Peters | Bob McClure | 281 | 292 | -11 |
| 1988-06-28 | @ SLN | 76 | L 4-5 | 35-41 | 5 | 36,113 | John Dopson | John Tudor | Ken Dayley | Joe Hesketh | | 285 | 297 | -12 |
| 1988-06-29 | @ SLN | 77 | W 3-2 | 36-41 | 5 | 37,921 | Dennis Martinez | Danny Cox | Jeff Parrett | Todd Worrell | | 288 | 299 | -11 |
| 1988-06-30 | vs ATL | 78 | W 6-0 | 37-41 | 5 | 10,461 | Brian Holman | Tom Glavine | Brian Holman | Tom Glavine | | 294 | 299 | -5 |
| 1988-07-01 | vs ATL | 79 | W 9-3 | 38-41 | 4 | 20,123 | Pascual Perez | Zane Smith | Pascual Perez | Zane Smith | Joe Hesketh | 303 | 302 | 1 |
| 1988-07-02 | vs ATL | 80 | L 4-5 | 38-42 | 4 | 15,797 | Bryn Smith | Rick Mahler | Paul Assenmacher | Neal Heaton | Charlie Puleo | 307 | 307 | 0 |
| 1988-07-03 | vs ATL | 81 | W 9-2 | 39-42 | 4 | 25,753 | John Dopson | German Jimenez | John Dopson | German Jimenez | | 316 | 309 | 7 |
| 1988-07-04 | @ HOU | 82 | W 7-4 | 40-42 | 4 | 15,130 | Dennis Martinez | Danny Darwin | Dennis Martinez | Danny Darwin | Jeff Parrett | 323 | 313 | 10 |
| 1988-07-05 | @ HOU | 83 | W 4-3 | 41-42 | 4 | 13,342 | Brian Holman | Joaquin Andujar | Jeff Parrett | Dave Smith | Neal Heaton | 327 | 316 | 11 |
| 1988-07-06 | @ HOU | 84 | W 4-2 | 42-42 | 4 | 13,553 | Pascual Perez | Jim Deshaies | Pascual Perez | Jim Deshaies | Joe Hesketh | 331 | 318 | 13 |
| 1988-07-08 | @ ATL | 85 | W 7-1 | 43-42 | 4 | 11,548 | Bryn Smith | Rick Mahler | Bryn Smith | Rick Mahler | | 338 | 319 | 19 |
| 1988-07-09 | @ ATL | 86 | W 9-4 | 44-42 | 4 | 16,747 | Dennis Martinez | Pete Smith | Dennis Martinez | Pete Smith | | 347 | 323 | 24 |
| 1988-07-10 | @ ATL | 87 | W 4-2 | 45-42 | 4 | 23,333 | Brian Holman | Tom Glavine | Jeff Parrett | Bruce Sutter | Neal Heaton | 351 | 325 | 26 |
| 1988-07-14 | vs CIN | 88 | W 1-0 | 46-42 | 3 | 28,813 | Pascual Perez | Danny Jackson | Jeff Parrett | Danny Jackson | | 352 | 325 | 27 |
| 1988-07-15 | vs CIN | 89 | L 3-6 | 46-43 | 3 | 22,184 | John Dopson | Jose Rijo | Jose Rijo | Jeff Parrett | John Franco | 355 | 331 | 24 |
| 1988-07-16 | vs CIN | 90 | W 6-1 | 47-43 | 3 | 26,288 | Dennis Martinez | Tom Browning | Dennis Martinez | Tom Browning | | 361 | 332 | 29 |
| 1988-07-17 | vs CIN | 91 | L 1-3 | 47-44 | 3 | 28,045 | Brian Holman | Jack Armstrong | Jack Armstrong | Brian Holman | John Franco | 362 | 335 | 27 |
| 1988-07-18 | vs HOU | 92 | L 1-6 | 47-45 | 4 | 17,390 | Bryn Smith | Joaquin Andujar | Joaquin Andujar | Bryn Smith | Danny Darwin | 363 | 341 | 22 |
| 1988-07-19 | vs HOU | 93 | L 3-4 | 47-46 | 4 | 30,757 | Pascual Perez | Mike Scott | Mike Scott | Pascual Perez | Dave Smith | 366 | 345 | 21 |
| 1988-07-20 | vs HOU | 94 | L 2-3 | 47-47 | 4 | 17,476 | John Dopson | Jim Deshaies | Jim Deshaies | John Dopson | Larry Andersen | 368 | 348 | 20 |
| 1988-07-21 | @ CIN | 95 | W 3-2 | 48-47 | 3 | 27,014 | Dennis Martinez | Tom Browning | Dennis Martinez | Frank Williams | Tim Burke | 371 | 350 | 21 |
| 1988-07-22 | @ CIN | 96 | L 1-4 | 48-48 | 4 | 31,543 | Brian Holman | Danny Jackson | Danny Jackson | Brian Holman | John Franco | 372 | 354 | 18 |
| 1988-07-23 | @ CIN | 97 | W 1-0 | 49-48 | 4 | 31,377 | Bryn Smith | Jose Rijo | Bryn Smith | Jose Rijo | Tim Burke | 373 | 354 | 19 |
| 1988-07-24 | @ CIN | 98 | W 5-3 | 50-48 | 3 | 28,786 | Pascual Perez | Jack Armstrong | Pascual Perez | Rob Dibble | Tim Burke | 378 | 357 | 21 |
| 1988-07-26 | vs CHN | 99 | W 8-4 | 51-48 | 3 | 26,029 | Dennis Martinez | Greg Maddux | Neal Heaton | Jeff Pico | | 386 | 361 | 25 |
| 1988-07-27 | vs CHN | 100 | W 5-4 | 52-48 | 3 | 18,227 | Brian Holman | Jamie Moyer | Joe Hesketh | Pat Perry | | 391 | 365 | 26 |
| 1988-07-28 | vs SLN | 101 | W 4-3 | 53-48 | 3 | 20,751 | Bryn Smith | Bob Forsch | Tim Burke | Larry McWilliams | | 395 | 368 | 27 |
| 1988-07-29 | vs SLN | 102 | L 5-7 | 53-49 | 3 | 32,198 | Pascual Perez | Jose DeLeon | Jose DeLeon | Pascual Perez | Todd Worrell | 400 | 375 | 25 |
| 1988-07-30 | vs SLN | 103 | W 2-1 | 54-49 | 3 | 24,719 | John Dopson | John Tudor | Joe Hesketh | Todd Worrell | | 402 | 376 | 26 |
| 1988-07-31 | vs SLN | 104 | W 2-0 | 55-49 | 3 | 35,016 | Dennis Martinez | Danny Cox | Dennis Martinez | Danny Cox | | 404 | 376 | 28 |
| 1988-08-02 | @ PIT | 105 | L 2-3 | 55-50 | 3 | 12,296 | Bryn Smith | Mike Dunne | Jim Gott | Neal Heaton | | 406 | 379 | 27 |
| 1988-08-03 | @ PIT | 106 | W 6-4 | 56-50 | 3 | 16,099 | Pascual Perez | John Smiley | Pascual Perez | John Smiley | Tim Burke | 412 | 383 | 29 |
| 1988-08-04 | @ PIT | 107 | W 3-2 | 57-50 | 3 | 17,726 | John Dopson | Brian Fisher | John Dopson | Brian Fisher | Tim Burke | 415 | 385 | 30 |
| 1988-08-05 | @ SLN | 108 | W 3-1 | 58-50 | 3 | 45,023 | Dennis Martinez | John Tudor | Dennis Martinez | John Tudor | | 418 | 386 | 32 |
| 1988-08-06 | @ SLN | 109 | W 5-4 | 59-50 | 3 | 36,338 | Brian Holman | Danny Cox | Brian Holman | Danny Cox | Tim Burke | 423 | 390 | 33 |
| 1988-08-07 | @ SLN | 110 | W 11-5 | 60-50 | 2 | 27,748 | Bryn Smith | Joe Magrane | Bryn Smith | Joe Magrane | Tim Barrett | 434 | 395 | 39 |
| 1988-08-08 | @ SLN | 111 | L 2-4 | 60-51 | 3 | 28,916 | Pascual Perez | Bob Forsch | Bob Forsch | Pascual Perez | Todd Worrell | 436 | 399 | 37 |
| 1988-08-09 | vs PIT | 112 | L 8-10 | 60-52 | 3 | 37,681 | John Dopson | Brian Fisher | Brian Fisher | John Dopson | Jim Gott | 444 | 409 | 35 |
| 1988-08-10 | vs PIT | 113 | W 5-4 | 61-52 | 3 | 29,196 | Dennis Martinez | Bob Walk | Dennis Martinez | Bob Walk | Tim Burke | 449 | 413 | 36 |
| 1988-08-11 | vs PIT | 114 | L 1-6 | 61-53 | 3 | 33,599 | Brian Holman | Doug Drabek | Doug Drabek | Brian Holman | Jim Gott | 450 | 419 | 31 |
| 1988-08-12 | @ NYN | 115 | W 5-2 | 62-53 | 3 | 46,380 | Bryn Smith | David Cone | Andy McGaffigan | Randy Myers | | 455 | 421 | 34 |
| 1988-08-13 | @ NYN | 116 | W 7-4 | 63-53 | 3 | 42,299 | Pascual Perez | Bob Ojeda | Pascual Perez | Bob Ojeda | Andy McGaffigan | 462 | 425 | 37 |
| 1988-08-14 | @ NYN | 117 | L 3-4 | 63-55 | 3 | 0 | John Dopson | Ron Darling | Roger McDowell | Neal Heaton | | 465 | 429 | 36 |
| 1988-08-14 | @ NYN | 118 | L 2-4 | 63-55 | 3 | 44,311 | Dennis Martinez | Sid Fernandez | Sid Fernandez | Dennis Martinez | Roger McDowell | 467 | 433 | 34 |
| 1988-08-16 | @ SDN | 119 | L 2-6 | 63-56 | 3 | 13,727 | Brian Holman | Jimmy Jones | Jimmy Jones | Brian Holman | Lance McCullers | 469 | 439 | 30 |
| 1988-08-17 | @ SDN | 120 | L 2-4 | 63-57 | 3 | 12,348 | Bryn Smith | Dennis Rasmussen | Dennis Rasmussen | Bryn Smith | Mark Davis | 471 | 443 | 28 |
| 1988-08-18 | @ SDN | 121 | L 4-5 | 63-58 | 3 | 15,648 | Pascual Perez | Ed Whitson | Lance McCullers | Tim Burke | | 475 | 448 | 27 |
| 1988-08-19 | @ LAN | 122 | L 0-2 | 63-59 | 3 | 36,217 | Dennis Martinez | Orel Hershiser | Orel Hershiser | Dennis Martinez | | 475 | 450 | 25 |
| 1988-08-20 | @ LAN | 123 | L 3-4 | 63-60 | 3 | 46,743 | John Dopson | Tim Belcher | Jay Howell | Joe Hesketh | | 478 | 454 | 24 |
| 1988-08-21 | @ LAN | 124 | L 0-4 | 63-61 | 3 | 39,505 | Neal Heaton | Tim Leary | Tim Leary | Neal Heaton | | 478 | 458 | 20 |
| 1988-08-22 | @ SFN | 125 | L 2-3 | 63-62 | 3 | 15,092 | Bryn Smith | Rick Reuschel | Rick Reuschel | Bryn Smith | | 480 | 461 | 19 |
| 1988-08-23 | @ SFN | 126 | W 2-1 | 64-62 | 3 | 16,191 | Pascual Perez | Mike Krukow | Andy McGaffigan | Scott Garrelts | Joe Hesketh | 482 | 462 | 20 |
| 1988-08-24 | @ SFN | 127 | W 7-5 | 65-62 | 3 | 19,533 | Dennis Martinez | Kelly Downs | Dennis Martinez | Roger Samuels | Joe Hesketh | 489 | 467 | 22 |
| 1988-08-26 | vs SDN | 128 | L 3-4 | 65-63 | 3 | 21,391 | John Dopson | Andy Hawkins | Andy Hawkins | John Dopson | Mark Davis | 492 | 471 | 21 |
| 1988-08-27 | vs SDN | 129 | W 4-0 | 66-63 | 3 | 20,986 | Bryn Smith | Jimmy Jones | Bryn Smith | Jimmy Jones | Joe Hesketh | 496 | 471 | 25 |
| 1988-08-28 | vs SDN | 130 | L 3-5 | 66-64 | 3 | 29,615 | Pascual Perez | Ed Whitson | Lance McCullers | Neal Heaton | | 499 | 476 | 23 |
| 1988-08-29 | vs LAN | 131 | L 1-2 | 66-65 | 4 | 16,002 | Dennis Martinez | Ramon Martinez | Ramon Martinez | Dennis Martinez | Jay Howell | 500 | 478 | 22 |
| 1988-08-30 | vs LAN | 132 | L 2-4 | 66-66 | 4 | 21,454 | Brian Holman | Orel Hershiser | Orel Hershiser | Brian Holman | | 502 | 482 | 20 |
| 1988-08-31 | vs LAN | 133 | W 4-3 | 67-66 | 4 | 12,068 | John Dopson | Tim Belcher | Jeff Parrett | Alejandro Pena | | 506 | 485 | 21 |
| 1988-09-02 | vs SFN | 134 | W 10-0 | 68-66 | 3 | 12,633 | Bryn Smith | Atlee Hammaker | Bryn Smith | Atlee Hammaker | | 516 | 485 | 31 |
| 1988-09-03 | vs SFN | 135 | W 6-4 | 69-66 | 3 | 16,563 | Pascual Perez | Don Robinson | Andy McGaffigan | Roger Samuels | | 522 | 489 | 33 |
| 1988-09-04 | vs SFN | 136 | W 3-2 | 70-66 | 3 | 27,395 | Brian Holman | Rick Reuschel | Brian Holman | Rick Reuschel | Tim Burke | 525 | 491 | 34 |
| 1988-09-05 | @ SLN | 137 | L 2-6 | 70-67 | 3 | 25,782 | John Dopson | Scott Terry | Scott Terry | John Dopson | | 527 | 497 | 30 |
| 1988-09-06 | @ SLN | 138 | L 0-1 | 70-68 | 3 | 18,902 | Dennis Martinez | Jose DeLeon | Jose DeLeon | Dennis Martinez | | 527 | 498 | 29 |
| 1988-09-07 | @ PIT | 139 | L 4-5 | 70-69 | 3 | 16,494 | Bryn Smith | Doug Drabek | Doug Drabek | Bryn Smith | Jim Gott | 531 | 503 | 28 |
| 1988-09-08 | @ PIT | 140 | W 5-4 | 71-69 | 3 | 11,289 | Pascual Perez | Bob Walk | Pascual Perez | Jeff Robinson | Joe Hesketh | 536 | 507 | 29 |
| 1988-09-09 | vs NYN | 141 | L 3-7 | 71-70 | 3 | 22,496 | Brian Holman | Sid Fernandez | Terry Leach | Brian Holman | Roger McDowell | 539 | 514 | 25 |
| 1988-09-10 | vs NYN | 142 | L 0-6 | 71-71 | 3 | 25,060 | John Dopson | David Cone | David Cone | John Dopson | | 539 | 520 | 19 |
| 1988-09-11 | vs NYN | 143 | L 0-3 | 71-72 | 3 | 32,567 | Dennis Martinez | Bob Ojeda | Bob Ojeda | Dennis Martinez | | 539 | 523 | 16 |
| 1988-09-12 | vs SLN | 144 | W 14-2 | 72-72 | 3 | 7,632 | Bryn Smith | Joe Magrane | Bryn Smith | Joe Magrane | Mike Smith | 553 | 525 | 28 |
| 1988-09-13 | vs SLN | 145 | W 7-1 | 73-72 | 3 | 8,623 | Pascual Perez | Larry McWilliams | Pascual Perez | Larry McWilliams | | 560 | 526 | 34 |
| 1988-09-14 | vs PIT | 146 | L 1-4 | 73-73 | 3 | 10,886 | Brian Holman | Mike Dunne | Brian Fisher | Tim Burke | | 561 | 530 | 31 |
| 1988-09-15 | vs PIT | 147 | W 9-4 | 74-73 | 3 | 9,494 | Randy Johnson | Dave LaPoint | Randy Johnson | Dave LaPoint | Andy McGaffigan | 570 | 534 | 36 |
| 1988-09-16 | @ NYN | 148 | L 3-4 | 74-74 | 3 | 43,331 | John Dopson | Bob Ojeda | Randy Myers | Joe Hesketh | | 573 | 538 | 35 |
| 1988-09-17 | @ NYN | 149 | L 2-6 | 74-75 | 3 | 46,109 | Bryn Smith | Ron Darling | Ron Darling | Bryn Smith | | 575 | 544 | 31 |
| 1988-09-18 | @ NYN | 150 | L 3-5 | 74-76 | 3 | 45,255 | Pascual Perez | Dwight Gooden | Dwight Gooden | Pascual Perez | Randy Myers | 578 | 549 | 29 |
| 1988-09-20 | @ CHN | 151 | L 4-5 | 75-77 | 3 | 0 | Dennis Martinez | Rick Sutcliffe | Rick Sutcliffe | Tim Burke | | 582 | 554 | 28 |
| 1988-09-20 | @ CHN | 152 | W 9-1 | 75-77 | 3 | 23,030 | Randy Johnson | Calvin Schiraldi | Randy Johnson | Calvin Schiraldi | | 591 | 555 | 36 |
| 1988-09-21 | @ CHN | 153 | W 8-5 | 76-77 | 3 | 8,360 | John Dopson | Mike Harkey | Joe Hesketh | Rich Gossage | Tim Burke | 599 | 560 | 39 |
| 1988-09-23 | @ PHI | 154 | W 3-2 | 77-77 | 3 | 13,386 | Bryn Smith | Kevin Gross | Jeff Parrett | Kent Tekulve | Tim Burke | 602 | 562 | 40 |
| 1988-09-24 | @ PHI | 155 | W 1-0 | 78-77 | 3 | 14,088 | Pascual Perez | Alex Madrid | Pascual Perez | Alex Madrid | | 603 | 562 | 41 |
| 1988-09-25 | @ PHI | 156 | L 5-8 | 78-78 | 3 | 20,188 | Dennis Martinez | Shane Rawley | Shane Rawley | Dennis Martinez | Steve Bedrosian | 608 | 570 | 38 |
| 1988-09-26 | vs CHN | 157 | W 3-2 | 79-78 | 3 | 6,577 | Randy Johnson | Mike Harkey | Randy Johnson | Mike Harkey | Tim Burke | 611 | 572 | 39 |
| 1988-09-27 | vs CHN | 158 | L 3-5 | 79-79 | 3 | 6,131 | Brian Holman | Calvin Schiraldi | Calvin Schiraldi | Brian Holman | Rich Gossage | 614 | 577 | 37 |
| 1988-09-28 | vs CHN | 159 | L 1-3 | 79-80 | 3 | 5,678 | John Dopson | Greg Maddux | Greg Maddux | John Dopson | | 615 | 580 | 35 |
| 1988-09-29 | vs CHN | 160 | W 5-4 | 80-80 | 3 | 6,300 | Bryn Smith | Mike Bielecki | Bryn Smith | Mike Bielecki | Tim Burke | 620 | 584 | 36 |
| 1988-09-30 | vs PHI | 161 | L 1-2 | 80-81 | 3 | 7,362 | Pascual Perez | Alex Madrid | Alex Madrid | Pascual Perez | Steve Bedrosian | 621 | 586 | 35 |
| 1988-10-01 | vs PHI | 162 | L 4-5 | 80-82 | 3 | 9,105 | Randy Johnson | Marvin Freeman | Mike Maddux | Jeff Parrett | Steve Bedrosian | 625 | 591 | 34 |
| 1988-10-02 | vs PHI | 163 | W 3-1 | 81-82 | 3 | 13,498 | Brian Holman | Don Carman | Brian Holman | Don Carman | Joe Hesketh | 628 | 592 | 36 |