| 2004-04-05 | @ PIT | 1 | L 1-2 | 0-1 | 5 | 35,702 | Kevin Millwood | Kip Wells | Kip Wells | Kevin Millwood | Jose Mesa | 1 | 2 | -1 |
| 2004-04-07 | @ PIT | 2 | W 5-4 | 1-1 | 5 | 15,126 | Randy Wolf | Kris Benson | Rheal Cormier | Brian Boehringer | Billy Wagner | 6 | 6 | 0 |
| 2004-04-08 | @ PIT | 3 | L 2-6 | 1-2 | 5 | 9,689 | Vicente Padilla | Ryan Vogelsong | Ryan Vogelsong | Vicente Padilla | Jose Mesa | 8 | 12 | -4 |
| 2004-04-09 | @ FLO | 4 | L 3-4 | 1-3 | 5 | 22,923 | Eric Milton | Carl Pavano | Matt Perisho | Rheal Cormier | Armando Benitez | 11 | 16 | -5 |
| 2004-04-10 | @ FLO | 5 | L 3-5 | 1-4 | 5 | 45,725 | Brett Myers | Darren Oliver | Darren Oliver | Rheal Cormier | Armando Benitez | 14 | 21 | -7 |
| 2004-04-11 | @ FLO | 6 | L 1-3 | 1-5 | 5 | 21,317 | Kevin Millwood | Josh Beckett | Josh Beckett | Kevin Millwood | Armando Benitez | 15 | 24 | -9 |
| 2004-04-12 | vs CIN | 7 | L 1-4 | 1-6 | 5 | 41,626 | Randy Wolf | Paul Wilson | Paul Wilson | Randy Wolf | Danny Graves | 16 | 28 | -12 |
| 2004-04-15 | vs CIN | 8 | W 6-4 | 2-6 | 4 | 37,512 | Vicente Padilla | Jose Acevedo | Rheal Cormier | Ryan Wagner | Billy Wagner | 22 | 32 | -10 |
| 2004-04-16 | vs MON | 9 | W 4-2 | 3-6 | 4 | 39,613 | Eric Milton | Livan Hernandez | Eric Milton | Livan Hernandez | Billy Wagner | 26 | 34 | -8 |
| 2004-04-17 | vs MON | 10 | W 6-3 | 4-6 | 4 | 42,931 | Kevin Millwood | John Patterson | Kevin Millwood | John Patterson | Billy Wagner | 32 | 37 | -5 |
| 2004-04-18 | vs MON | 11 | W 5-4 | 5-6 | 3 | 43,791 | Randy Wolf | Claudio Vargas | Billy Wagner | Rocky Biddle | | 37 | 41 | -4 |
| 2004-04-20 | vs FLO | 12 | L 1-3 | 5-7 | 4 | 36,479 | Vicente Padilla | Dontrelle Willis | Dontrelle Willis | Vicente Padilla | Armando Benitez | 38 | 44 | -6 |
| 2004-04-21 | vs FLO | 13 | L 7-8 | 5-8 | 4 | 34,060 | Eric Milton | Carl Pavano | Justin Wayne | Ryan Madson | | 45 | 52 | -7 |
| 2004-04-22 | vs FLO | 14 | L 7-9 | 5-9 | 4 | 35,880 | Brett Myers | Darren Oliver | Darren Oliver | Brett Myers | Armando Benitez | 52 | 61 | -9 |
| 2004-04-23 | @ MON | 15 | W 8-6 | 6-9 | 4 | 30,112 | Kevin Millwood | Claudio Vargas | Kevin Millwood | Chad Bentz | Billy Wagner | 60 | 67 | -7 |
| 2004-04-24 | @ MON | 16 | W 7-0 | 7-9 | 3 | 6,899 | Randy Wolf | Tomo Ohka | Randy Wolf | Tomo Ohka | | 67 | 67 | 0 |
| 2004-04-25 | @ MON | 17 | L 0-2 | 7-10 | 3 | 8,267 | Vicente Padilla | Zach Day | Zach Day | Vicente Padilla | Rocky Biddle | 67 | 69 | -2 |
| 2004-04-27 | @ SLN | 18 | W 7-3 | 8-10 | 3 | 25,185 | Eric Milton | Matt Morris | Eric Milton | Matt Morris | | 74 | 72 | 2 |
| 2004-04-28 | @ SLN | 19 | W 6-3 | 9-10 | 3 | 26,348 | Brett Myers | Jason Marquis | Ryan Madson | Mike Lincoln | Billy Wagner | 80 | 75 | 5 |
| 2004-04-29 | @ SLN | 20 | L 4-5 | 9-11 | 3 | 29,768 | Kevin Millwood | Chris Carpenter | Mike Lincoln | Amaury Telemaco | | 84 | 80 | 4 |
| 2004-04-30 | vs ARI | 21 | W 4-0 | 10-11 | 3 | 43,721 | Randy Wolf | Elmer Dessens | Randy Wolf | Elmer Dessens | | 88 | 80 | 8 |
| 2004-05-01 | vs ARI | 22 | L 4-6 | 10-12 | 3 | 44,048 | Vicente Padilla | Randy Johnson | Randy Johnson | Vicente Padilla | Matt Mantei | 92 | 86 | 6 |
| 2004-05-02 | vs ARI | 23 | W 6-5 | 11-12 | 3 | 43,025 | Eric Milton | Brandon Webb | Ryan Madson | Oscar Villarreal | | 98 | 91 | 7 |
| 2004-05-04 | vs SLN | 24 | L 5-6 | 11-13 | 3 | 33,294 | Brett Myers | Chris Carpenter | Chris Carpenter | Brett Myers | Jason Isringhausen | 103 | 97 | 6 |
| 2004-05-05 | vs SLN | 25 | W 5-4 | 12-13 | 3 | 35,944 | Kevin Millwood | Woody Williams | Kevin Millwood | Woody Williams | Billy Wagner | 108 | 101 | 7 |
| 2004-05-06 | vs SLN | 26 | L 4-7 | 12-14 | 4 | 44,376 | Randy Wolf | Jeff Suppan | Jeff Suppan | Randy Wolf | Jason Isringhausen | 112 | 108 | 4 |
| 2004-05-07 | @ ARI | 27 | W 4-1 | 13-14 | 2 | 30,738 | Vicente Padilla | Randy Johnson | Vicente Padilla | Randy Johnson | Billy Wagner | 116 | 109 | 7 |
| 2004-05-08 | @ ARI | 28 | W 8-7 | 14-14 | 2 | 38,907 | Eric Milton | Brandon Webb | Eric Milton | Brandon Webb | Tim Worrell | 124 | 116 | 8 |
| 2004-05-09 | @ ARI | 29 | W 7-1 | 15-14 | 2 | 29,637 | Brett Myers | Steve Sparks | Brett Myers | Steve Sparks | | 131 | 117 | 14 |
| 2004-05-11 | @ SFN | 30 | W 10-4 | 16-14 | 2 | 35,759 | Kevin Millwood | Jerome Williams | Kevin Millwood | Jerome Williams | | 141 | 121 | 20 |
| 2004-05-12 | @ SFN | 31 | L 3-4 | 16-15 | 2 | 35,849 | Randy Wolf | Jason Schmidt | Jason Schmidt | Randy Wolf | Matt Herges | 144 | 125 | 19 |
| 2004-05-13 | @ SFN | 32 | W 4-3 | 17-15 | 2 | 39,651 | Vicente Padilla | Kirk Rueter | Vicente Padilla | Kirk Rueter | Ryan Madson | 148 | 128 | 20 |
| 2004-05-14 | @ COL | 33 | W 6-4 | 18-15 | 2 | 32,171 | Eric Milton | Joe Kennedy | Eric Milton | Joe Kennedy | Tim Worrell | 154 | 132 | 22 |
| 2004-05-15 | @ COL | 34 | W 16-5 | 19-15 | 1 | 33,629 | Brett Myers | Scott Elarton | Brett Myers | Scott Elarton | | 170 | 137 | 33 |
| 2004-05-16 | @ COL | 35 | L 6-7 | 19-16 | 2 | 33,623 | Kevin Millwood | Jason Young | Tim Harikkala | Rheal Cormier | Shawn Chacon | 176 | 144 | 32 |
| 2004-05-17 | @ COL | 36 | L 6-7 | 19-17 | 2 | 22,111 | Randy Wolf | Aaron Cook | Brian Fuentes | Tim Worrell | | 182 | 151 | 31 |
| 2004-05-18 | vs LAN | 37 | W 8-7 | 20-17 | 2 | 36,073 | Vicente Padilla | Wilson Alvarez | Vicente Padilla | Guillermo Mota | Tim Worrell | 190 | 158 | 32 |
| 2004-05-19 | vs LAN | 38 | W 9-4 | 21-17 | 1 | 33,916 | Eric Milton | Hideo Nomo | Eric Milton | Hideo Nomo | | 199 | 162 | 37 |
| 2004-05-20 | vs LAN | 39 | W 4-0 | 22-17 | 1 | 37,793 | Brett Myers | Kazuhisa Ishii | Brett Myers | Kazuhisa Ishii | | 203 | 162 | 41 |
| 2004-05-21 | vs SDN | 40 | W 5-4 | 23-17 | 1 | 40,555 | Kevin Millwood | Adam Eaton | Ryan Madson | Akinori Otsuka | Tim Worrell | 208 | 166 | 42 |
| 2004-05-22 | vs SDN | 41 | L 6-9 | 23-18 | 2 | 43,634 | Josh Hancock | Justin Germano | Justin Germano | Roberto Hernandez | | 214 | 175 | 39 |
| 2004-05-23 | vs SDN | 42 | W 6-4 | 24-18 | 1 | 44,216 | Vicente Padilla | Brian Lawrence | Vicente Padilla | Brian Lawrence | Tim Worrell | 220 | 179 | 41 |
| 2004-05-25 | @ NYN | 43 | L 0-5 | 24-19 | 1 | 29,385 | Eric Milton | Steve Trachsel | Steve Trachsel | Eric Milton | | 220 | 184 | 36 |
| 2004-05-26 | @ NYN | 44 | W 7-4 | 25-19 | 1 | 20,349 | Brett Myers | Matt Ginter | Roberto Hernandez | John Franco | Tim Worrell | 227 | 188 | 39 |
| 2004-05-27 | vs ATL | 45 | L 1-6 | 25-20 | 2 | 38,802 | Kevin Millwood | Jaret Wright | Jaret Wright | Kevin Millwood | | 228 | 194 | 34 |
| 2004-05-28 | vs ATL | 46 | W 3-2 | 26-20 | 2 | 40,187 | Randy Wolf | Mike Hampton | Tim Worrell | Antonio Alfonseca | | 231 | 196 | 35 |
| 2004-05-29 | vs ATL | 47 | L 3-9 | 26-21 | 2 | 44,057 | Vicente Padilla | John Thomson | John Thomson | Vicente Padilla | | 234 | 205 | 29 |
| 2004-05-30 | vs ATL | 48 | W 4-1 | 27-21 | 2 | 44,304 | Eric Milton | Travis Smith | Eric Milton | Travis Smith | Tim Worrell | 238 | 206 | 32 |
| 2004-05-31 | vs NYN | 49 | L 3-5 | 27-22 | 2 | 43,620 | Brett Myers | Matt Ginter | Orber Moreno | Brett Myers | Braden Looper | 241 | 211 | 30 |
| 2004-06-01 | vs NYN | 50 | L 1-4 | 27-23 | 2 | 34,436 | Kevin Millwood | Al Leiter | Ricky Bottalico | Tim Worrell | Braden Looper | 242 | 215 | 27 |
| 2004-06-02 | vs NYN | 51 | L 3-5 | 27-24 | 2 | 37,625 | Randy Wolf | Tom Glavine | David Weathers | Roberto Hernandez | Braden Looper | 245 | 220 | 25 |
| 2004-06-03 | @ ATL | 52 | L 4-8 | 27-25 | 2 | 23,405 | Josh Hancock | John Thomson | John Thomson | Josh Hancock | | 249 | 228 | 21 |
| 2004-06-04 | @ ATL | 53 | W 9-1 | 28-25 | 2 | 27,699 | Eric Milton | Travis Smith | Eric Milton | Travis Smith | | 258 | 229 | 29 |
| 2004-06-05 | @ ATL | 54 | W 5-3 | 29-25 | 2 | 29,252 | Brett Myers | Russ Ortiz | Brett Myers | Russ Ortiz | Tim Worrell | 263 | 232 | 31 |
| 2004-06-06 | @ ATL | 55 | L 4-6 | 29-26 | 2 | 27,775 | Kevin Millwood | Jaret Wright | Jaret Wright | Kevin Millwood | John Smoltz | 267 | 238 | 29 |
| 2004-06-08 | @ CHA | 56 | L 11-14 | 29-27 | 2 | 33,114 | Ryan Madson | Mark Buehrle | Mark Buehrle | Amaury Telemaco | Cliff Politte | 278 | 252 | 26 |
| 2004-06-09 | @ CHA | 57 | W 13-10 | 30-27 | 2 | 17,570 | Eric Milton | Jon Garland | Eric Milton | Jon Garland | | 291 | 262 | 29 |
| 2004-06-11 | @ MIN | 58 | W 11-6 | 31-27 | 2 | 22,272 | Brett Myers | Seth Greisinger | Tim Worrell | Terry Mulholland | | 302 | 268 | 34 |
| 2004-06-12 | @ MIN | 59 | L 1-6 | 31-28 | 2 | 22,219 | Kevin Millwood | Carlos Silva | Carlos Silva | Kevin Millwood | | 303 | 274 | 29 |
| 2004-06-13 | @ MIN | 60 | W 2-1 | 32-28 | 2 | 23,479 | Paul Abbott | Brad Radke | Rheal Cormier | Aaron Fultz | Billy Wagner | 305 | 275 | 30 |
| 2004-06-14 | vs CIN | 61 | W 10-7 | 33-28 | 2 | 44,710 | Eric Milton | Jose Acevedo | Ryan Madson | John Riedling | | 315 | 282 | 33 |
| 2004-06-15 | vs DET | 62 | L 3-10 | 33-29 | 2 | 39,555 | Brian Powell | Jeremy Bonderman | Jeremy Bonderman | Brian Powell | | 318 | 292 | 26 |
| 2004-06-17 | vs DET | 63 | W 6-2 | 34-30 | 2 | 44,551 | Brett Myers | Mike Maroth | Brett Myers | Mike Maroth | | 324 | 294 | 30 |
| 2004-06-17 | vs DET | 64 | L 4-5 | 34-30 | 2 | 39,674 | Kevin Millwood | Gary Knotts | Ugueth Urbina | Ryan Madson | Danny Patterson | 328 | 299 | 29 |
| 2004-06-18 | vs KCA | 65 | L 4-10 | 34-31 | 2 | 43,571 | Paul Abbott | Chris George | Chris George | Paul Abbott | | 332 | 309 | 23 |
| 2004-06-19 | vs KCA | 66 | W 4-2 | 35-31 | 2 | 44,234 | Eric Milton | Zack Greinke | Eric Milton | Zack Greinke | Billy Wagner | 336 | 311 | 25 |
| 2004-06-20 | vs KCA | 67 | W 8-2 | 36-31 | 1 | 44,411 | Brian Powell | Dennys Reyes | Brian Powell | Dennys Reyes | | 344 | 313 | 31 |
| 2004-06-22 | @ MON | 68 | L 2-5 | 36-32 | 2 | 4,564 | Brett Myers | Livan Hernandez | Livan Hernandez | Brett Myers | Chad Cordero | 346 | 318 | 28 |
| 2004-06-23 | @ MON | 69 | W 5-2 | 37-32 | 2 | 4,209 | Kevin Millwood | Sun-Woo Kim | Kevin Millwood | Sun-Woo Kim | Billy Wagner | 351 | 320 | 31 |
| 2004-06-24 | @ MON | 70 | L 2-3 | 37-33 | 2 | 11,655 | Eric Milton | Tony Armas | Tony Armas | Eric Milton | Chad Cordero | 353 | 323 | 30 |
| 2004-06-25 | @ BOS | 71 | L 1-12 | 37-34 | 2 | 35,059 | Paul Abbott | Pedro Martinez | Pedro Martinez | Paul Abbott | | 354 | 335 | 19 |
| 2004-06-26 | @ BOS | 72 | W 9-2 | 38-34 | 1 | 34,712 | Randy Wolf | Bronson Arroyo | Ryan Madson | Bronson Arroyo | | 363 | 337 | 26 |
| 2004-06-27 | @ BOS | 73 | L 3-12 | 38-35 | 2 | 34,739 | Brett Myers | Curt Schilling | Curt Schilling | Brett Myers | | 366 | 349 | 17 |
| 2004-06-28 | vs MON | 74 | W 14-6 | 39-35 | 1 | 39,444 | Kevin Millwood | Sun-Woo Kim | Kevin Millwood | Sun-Woo Kim | | 380 | 355 | 25 |
| 2004-06-29 | vs MON | 75 | W 17-7 | 40-35 | 1 | 35,390 | Eric Milton | Shawn Hill | Eric Milton | Shawn Hill | | 397 | 362 | 35 |
| 2004-06-30 | vs MON | 76 | L 3-6 | 40-36 | 1 | 40,407 | Paul Abbott | Zach Day | Joe Horgan | Tim Worrell | Chad Cordero | 400 | 368 | 32 |
| 2004-07-01 | vs MON | 77 | W 10-5 | 41-36 | 1 | 43,246 | Randy Wolf | Scott Downs | Randy Wolf | Scott Downs | | 410 | 373 | 37 |
| 2004-07-02 | vs BAL | 78 | L 6-7 | 41-37 | 1 | 44,390 | Brett Myers | Matt Riley | Eddy Rodriguez | Brian Powell | Daniel Cabrera | 416 | 380 | 36 |
| 2004-07-03 | vs BAL | 79 | W 7-6 | 42-37 | 1 | 44,163 | Kevin Millwood | Erik Bedard | Rheal Cormier | Jason Grimsley | Billy Wagner | 423 | 386 | 37 |
| 2004-07-04 | vs BAL | 80 | W 5-2 | 43-37 | 1 | 43,396 | Eric Milton | Sidney Ponson | Eric Milton | Sidney Ponson | Tim Worrell | 428 | 388 | 40 |
| 2004-07-05 | vs NYN | 81 | W 6-5 | 44-37 | 1 | 41,571 | Paul Abbott | Tom Glavine | Ryan Madson | Tom Glavine | Billy Wagner | 434 | 393 | 41 |
| 2004-07-06 | vs NYN | 82 | L 1-4 | 44-38 | 1 | 36,230 | Randy Wolf | Al Leiter | Al Leiter | Randy Wolf | Braden Looper | 435 | 397 | 38 |
| 2004-07-07 | vs NYN | 83 | L 1-10 | 44-39 | 1 | 37,687 | Brett Myers | Steve Trachsel | Steve Trachsel | Brett Myers | | 436 | 407 | 29 |
| 2004-07-08 | vs NYN | 84 | W 5-4 | 45-39 | 1 | 42,601 | Kevin Millwood | Matt Ginter | Billy Wagner | John Franco | | 441 | 411 | 30 |
| 2004-07-09 | vs ATL | 85 | W 7-6 | 46-39 | 1 | 44,180 | Eric Milton | John Thomson | Billy Wagner | Antonio Alfonseca | | 448 | 417 | 31 |
| 2004-07-10 | vs ATL | 86 | L 0-4 | 46-40 | 1 | 44,307 | Paul Abbott | Mike Hampton | Mike Hampton | Paul Abbott | | 448 | 421 | 27 |
| 2004-07-11 | vs ATL | 87 | L 4-6 | 46-41 | 1 | 44,519 | Randy Wolf | Russ Ortiz | Russ Ortiz | Randy Wolf | John Smoltz | 452 | 427 | 25 |
| 2004-07-15 | @ NYN | 88 | L 2-3 | 46-42 | 2 | 36,803 | Eric Milton | Steve Trachsel | Jose Parra | Roberto Hernandez | | 454 | 430 | 24 |
| 2004-07-16 | @ NYN | 89 | W 5-1 | 47-42 | 1 | 42,584 | Kevin Millwood | Jae Weong Seo | Kevin Millwood | Jae Weong Seo | Billy Wagner | 459 | 431 | 28 |
| 2004-07-17 | @ NYN | 90 | W 8-2 | 48-42 | 1 | 35,425 | Randy Wolf | Tom Glavine | Randy Wolf | Tom Glavine | | 467 | 433 | 34 |
| 2004-07-18 | @ NYN | 91 | L 1-6 | 48-43 | 2 | 30,443 | Brett Myers | Al Leiter | Al Leiter | Brett Myers | Braden Looper | 468 | 439 | 29 |
| 2004-07-19 | @ ATL | 92 | L 2-4 | 48-44 | 2 | 25,790 | Paul Abbott | Mike Hampton | Mike Hampton | Paul Abbott | John Smoltz | 470 | 443 | 27 |
| 2004-07-20 | @ ATL | 93 | W 4-3 | 49-44 | 2 | 36,006 | Eric Milton | Jaret Wright | Tim Worrell | Antonio Alfonseca | Billy Wagner | 474 | 446 | 28 |
| 2004-07-21 | vs FLO | 94 | W 2-1 | 50-44 | 1 | 44,077 | Kevin Millwood | A.J. Burnett | Kevin Millwood | A.J. Burnett | Billy Wagner | 476 | 447 | 29 |
| 2004-07-22 | vs FLO | 95 | L 8-10 | 50-45 | 2 | 44,316 | Randy Wolf | Carl Pavano | Carl Pavano | Randy Wolf | Armando Benitez | 484 | 457 | 27 |
| 2004-07-23 | vs CHN | 96 | L 1-5 | 50-46 | 2 | 44,060 | Brett Myers | Kerry Wood | Kerry Wood | Brett Myers | | 485 | 462 | 23 |
| 2004-07-24 | vs CHN | 97 | W 4-3 | 51-46 | 2 | 44,493 | Paul Abbott | Carlos Zambrano | Paul Abbott | Carlos Zambrano | Tim Worrell | 489 | 465 | 24 |
| 2004-07-25 | vs CHN | 98 | W 3-2 | 52-46 | 2 | 44,539 | Eric Milton | Mark Prior | Ryan Madson | LaTroy Hawkins | | 492 | 467 | 25 |
| 2004-07-26 | @ FLO | 99 | L 3-11 | 52-47 | 2 | 13,507 | Kevin Millwood | A.J. Burnett | A.J. Burnett | Kevin Millwood | Nate Bump | 495 | 478 | 17 |
| 2004-07-27 | @ FLO | 100 | L 2-5 | 52-48 | 2 | 15,523 | Randy Wolf | Carl Pavano | Carl Pavano | Rheal Cormier | Josias Manzanillo | 497 | 483 | 14 |
| 2004-07-28 | @ FLO | 101 | L 3-6 | 52-49 | 2 | 17,404 | Brett Myers | Brad Penny | Josias Manzanillo | Tim Worrell | | 500 | 489 | 11 |
| 2004-07-29 | @ FLO | 102 | L 1-10 | 52-50 | 3 | 20,391 | Paul Abbott | Dontrelle Willis | Dontrelle Willis | Paul Abbott | | 501 | 499 | 2 |
| 2004-07-30 | @ CHN | 103 | L 7-10 | 52-51 | 3 | 39,117 | Eric Milton | Mark Prior | Jon Leicester | Rheal Cormier | LaTroy Hawkins | 508 | 509 | -1 |
| 2004-07-31 | @ CHN | 104 | W 4-3 | 53-51 | 2 | 39,086 | Kevin Millwood | Matt Clement | Kevin Millwood | Matt Clement | Tim Worrell | 512 | 512 | 0 |
| 2004-08-01 | @ CHN | 105 | L 3-6 | 53-52 | 2 | 39,032 | Randy Wolf | Greg Maddux | Kent Mercker | Randy Wolf | LaTroy Hawkins | 515 | 518 | -3 |
| 2004-08-03 | @ SDN | 106 | W 5-2 | 54-52 | 2 | 37,134 | Brett Myers | Brian Lawrence | Brett Myers | Brian Lawrence | | 520 | 520 | 0 |
| 2004-08-04 | @ SDN | 107 | W 7-5 | 55-52 | 2 | 30,085 | Eric Milton | Adam Eaton | Eric Milton | Adam Eaton | Tim Worrell | 527 | 525 | 2 |
| 2004-08-05 | @ SDN | 108 | W 5-3 | 56-52 | 2 | 36,127 | Kevin Millwood | Sterling Hitchcock | Felix Rodriguez | Trevor Hoffman | Tim Worrell | 532 | 528 | 4 |
| 2004-08-06 | @ LAN | 109 | W 9-5 | 57-52 | 2 | 53,977 | Randy Wolf | Kazuhisa Ishii | Roberto Hernandez | Eric Gagne | | 541 | 533 | 8 |
| 2004-08-07 | @ LAN | 110 | L 3-6 | 57-53 | 2 | 54,404 | Paul Abbott | Odalis Perez | Odalis Perez | Paul Abbott | Eric Gagne | 544 | 539 | 5 |
| 2004-08-08 | @ LAN | 111 | W 4-1 | 58-53 | 2 | 53,840 | Brett Myers | Brad Penny | Brett Myers | Brad Penny | | 548 | 540 | 8 |
| 2004-08-09 | vs COL | 112 | L 2-4 | 58-54 | 2 | 42,031 | Eric Milton | Jamey Wright | Tim Harikkala | Todd Jones | Shawn Chacon | 550 | 544 | 6 |
| 2004-08-10 | vs COL | 113 | L 4-5 | 58-55 | 2 | 36,636 | Vicente Padilla | Joe Kennedy | Steve Reed | Tim Worrell | Shawn Chacon | 554 | 549 | 5 |
| 2004-08-11 | vs COL | 114 | W 15-4 | 59-55 | 2 | 40,634 | Randy Wolf | Jason Jennings | Randy Wolf | Jason Jennings | | 569 | 553 | 16 |
| 2004-08-12 | vs COL | 115 | L 1-3 | 59-56 | 2 | 37,464 | Cory Lidle | Shawn Estes | Shawn Estes | Cory Lidle | Shawn Chacon | 570 | 556 | 14 |
| 2004-08-13 | vs SFN | 116 | L 6-16 | 59-57 | 2 | 43,036 | Brett Myers | Brad Hennessey | Brad Hennessey | Brett Myers | | 576 | 572 | 4 |
| 2004-08-14 | vs SFN | 117 | L 6-7 | 59-58 | 2 | 43,712 | Eric Milton | Noah Lowry | Jason Christiansen | Felix Rodriguez | Dustin Hermanson | 582 | 579 | 3 |
| 2004-08-15 | vs SFN | 118 | L 1-3 | 59-59 | 3 | 43,610 | Vicente Padilla | Brett Tomko | Brett Tomko | Vicente Padilla | Dustin Hermanson | 583 | 582 | 1 |
| 2004-08-17 | vs HOU | 119 | L 0-5 | 59-60 | 3 | 43,716 | Randy Wolf | Roy Oswalt | Roy Oswalt | Randy Wolf | | 583 | 587 | -4 |
| 2004-08-18 | vs HOU | 120 | L 8-9 | 59-61 | 3 | 43,895 | Cory Lidle | Roger Clemens | Chad Harville | Todd Jones | Brad Lidge | 591 | 596 | -5 |
| 2004-08-19 | vs HOU | 121 | L 10-12 | 59-62 | 3 | 43,543 | Brett Myers | Carlos Hernandez | Chad Qualls | Roberto Hernandez | Brad Lidge | 601 | 608 | -7 |
| 2004-08-20 | @ MIL | 122 | W 4-2 | 60-62 | 3 | 22,559 | Eric Milton | Doug Davis | Eric Milton | Doug Davis | Tim Worrell | 605 | 610 | -5 |
| 2004-08-21 | @ MIL | 123 | W 8-6 | 61-62 | 3 | 30,841 | Vicente Padilla | Wes Obermueller | Geoff Geary | Luis Vizcaino | Tim Worrell | 613 | 616 | -3 |
| 2004-08-22 | @ MIL | 124 | W 9-6 | 62-62 | 3 | 32,411 | Randy Wolf | Victor Santos | Felix Rodriguez | Danny Kolb | Tim Worrell | 622 | 622 | 0 |
| 2004-08-23 | @ HOU | 125 | L 4-8 | 62-63 | 3 | 36,398 | Cory Lidle | Roger Clemens | Roger Clemens | Cory Lidle | | 626 | 630 | -4 |
| 2004-08-24 | @ HOU | 126 | L 2-4 | 62-64 | 3 | 37,127 | Brett Myers | Carlos Hernandez | Roy Oswalt | Todd Jones | Brad Lidge | 628 | 634 | -6 |
| 2004-08-25 | @ HOU | 127 | L 4-7 | 62-65 | 3 | 37,217 | Eric Milton | Peter Munro | Chad Qualls | Felix Rodriguez | Brad Lidge | 632 | 641 | -9 |
| 2004-08-27 | vs MIL | 128 | W 6-1 | 63-65 | 3 | 40,367 | Vicente Padilla | Victor Santos | Vicente Padilla | Victor Santos | | 638 | 642 | -4 |
| 2004-08-28 | vs MIL | 129 | W 4-3 | 64-65 | 3 | 43,267 | Randy Wolf | Ben Sheets | Tim Worrell | Mike Adams | | 642 | 645 | -3 |
| 2004-08-29 | vs MIL | 130 | W 10-0 | 65-65 | 3 | 43,339 | Cory Lidle | Wes Obermueller | Cory Lidle | Wes Obermueller | | 652 | 645 | 7 |
| 2004-08-30 | @ CHA | 131 | L 8-9 | 65-66 | 3 | 5,747 | Brett Myers | Mark Buehrle | Mark Buehrle | Roberto Hernandez | Shingo Takatsu | 660 | 654 | 6 |
| 2004-08-31 | vs ATL | 132 | L 3-5 | 65-67 | 3 | 36,028 | Eric Milton | Mike Hampton | Mike Hampton | Eric Milton | | 663 | 659 | 4 |
| 2004-09-01 | vs ATL | 133 | L 2-7 | 65-68 | 3 | 35,031 | Vicente Padilla | Jaret Wright | Jaret Wright | Vicente Padilla | | 665 | 666 | -1 |
| 2004-09-03 | vs NYN | 134 | W 8-1 | 66-68 | 3 | 37,267 | Gavin Floyd | Matt Ginter | Gavin Floyd | Heath Bell | | 673 | 667 | 6 |
| 2004-09-04 | vs NYN | 135 | W 7-0 | 67-68 | 3 | 43,089 | Cory Lidle | Al Leiter | Cory Lidle | Al Leiter | | 680 | 667 | 13 |
| 2004-09-05 | vs NYN | 136 | W 4-2 | 68-68 | 3 | 43,628 | Brett Myers | Steve Trachsel | Brett Myers | Steve Trachsel | Tim Worrell | 684 | 669 | 15 |
| 2004-09-06 | @ ATL | 137 | L 1-3 | 68-69 | 3 | 31,949 | Eric Milton | Travis Smith | Travis Smith | Eric Milton | John Smoltz | 685 | 672 | 13 |
| 2004-09-08 | @ ATL | 138 | W 5-3 | 70-69 | 3 | 0 | Vicente Padilla | Jaret Wright | Ryan Madson | Chris Reitsma | Billy Wagner | 690 | 675 | 15 |
| 2004-09-08 | @ ATL | 139 | W 4-1 | 70-69 | 3 | 20,320 | Gavin Floyd | Paul Byrd | Todd Jones | Paul Byrd | Tim Worrell | 694 | 676 | 18 |
| 2004-09-09 | @ ATL | 140 | W 9-4 | 71-69 | 3 | 20,285 | Cory Lidle | Russ Ortiz | Ryan Madson | Roman Colon | | 703 | 680 | 23 |
| 2004-09-10 | @ NYN | 141 | W 9-5 | 72-69 | 3 | 27,827 | Brett Myers | Al Leiter | Todd Jones | Ricky Bottalico | | 712 | 685 | 27 |
| 2004-09-11 | @ NYN | 142 | W 11-9 | 73-69 | 3 | 21,718 | Eric Milton | Steve Trachsel | Roberto Hernandez | Vic Darensbourg | Felix Rodriguez | 723 | 694 | 29 |
| 2004-09-12 | @ NYN | 143 | W 4-2 | 74-69 | 3 | 23,391 | Vicente Padilla | Tom Glavine | Vicente Padilla | Tom Glavine | Tim Worrell | 727 | 696 | 31 |
| 2004-09-13 | @ CIN | 144 | L 3-4 | 74-70 | 3 | 15,930 | Gavin Floyd | Paul Wilson | Joe Valentine | Felix Rodriguez | Danny Graves | 730 | 700 | 30 |
| 2004-09-14 | @ CIN | 145 | L 6-7 | 74-71 | 3 | 15,364 | Cory Lidle | Jose Acevedo | Ryan Wagner | Ryan Madson | Danny Graves | 736 | 707 | 29 |
| 2004-09-15 | @ CIN | 146 | W 9-1 | 75-71 | 3 | 16,292 | Brett Myers | Brandon Claussen | Brett Myers | Brandon Claussen | | 745 | 708 | 37 |
| 2004-09-17 | vs MON | 147 | L 8-12 | 75-72 | 3 | 35,498 | Eric Milton | Claudio Vargas | Luis Ayala | Tim Worrell | | 753 | 720 | 33 |
| 2004-09-18 | vs MON | 148 | L 5-6 | 75-73 | 3 | 38,650 | Vicente Padilla | Sun-Woo Kim | Chad Cordero | Brett Myers | Francis Beltran | 758 | 726 | 32 |
| 2004-09-19 | vs MON | 149 | W 7-2 | 76-73 | 3 | 42,603 | Kevin Millwood | Scott Downs | Gavin Floyd | Scott Downs | | 765 | 728 | 37 |
| 2004-09-21 | @ FLO | 150 | W 4-2 | 77-73 | 3 | 15,659 | Cory Lidle | Dontrelle Willis | Cory Lidle | Dontrelle Willis | Billy Wagner | 769 | 730 | 39 |
| 2004-09-22 | @ FLO | 151 | W 12-4 | 78-73 | 3 | 20,416 | Eric Milton | Logan Kensing | Eric Milton | Logan Kensing | | 781 | 734 | 47 |
| 2004-09-23 | @ FLO | 152 | W 9-8 | 79-73 | 3 | 30,208 | Vicente Padilla | Josh Beckett | Billy Wagner | Armando Benitez | Todd Jones | 790 | 742 | 48 |
| 2004-09-24 | @ MON | 153 | L 1-8 | 79-74 | 3 | 5,481 | Brett Myers | Sun-Woo Kim | Sun-Woo Kim | Brett Myers | | 791 | 750 | 41 |
| 2004-09-25 | @ MON | 154 | W 4-3 | 80-74 | 2 | 8,491 | Kevin Millwood | Scott Downs | Tim Worrell | Joey Eischen | Billy Wagner | 795 | 753 | 42 |
| 2004-09-26 | @ MON | 155 | W 2-1 | 81-74 | 2 | 12,382 | Cory Lidle | Livan Hernandez | Cory Lidle | Livan Hernandez | Billy Wagner | 797 | 754 | 43 |
| 2004-09-27 | vs PIT | 156 | L 1-6 | 81-75 | 2 | 30,268 | Eric Milton | Oliver Perez | Oliver Perez | Eric Milton | | 798 | 760 | 38 |
| 2004-09-29 | vs PIT | 157 | W 8-4 | 83-75 | 2 | 0 | Vicente Padilla | Ian Snell | Vicente Padilla | Ian Snell | | 806 | 764 | 42 |
| 2004-09-29 | vs PIT | 158 | W 8-3 | 83-75 | 2 | 33,127 | Brett Myers | Ryan Vogelsong | Brett Myers | Salomon Torres | | 814 | 767 | 47 |
| 2004-09-30 | vs FLO | 159 | W 7-4 | 84-75 | 2 | 36,080 | Gavin Floyd | Dontrelle Willis | Todd Jones | Guillermo Mota | Billy Wagner | 821 | 771 | 50 |
| 2004-10-01 | vs FLO | 160 | W 6-2 | 85-75 | 2 | 34,494 | Cory Lidle | David Weathers | Cory Lidle | Matt Perisho | | 827 | 773 | 54 |
| 2004-10-02 | vs FLO | 161 | L 3-4 | 85-76 | 2 | 36,279 | Eric Milton | Josh Beckett | Josh Beckett | Eric Milton | Armando Benitez | 830 | 777 | 53 |
| 2004-10-03 | vs FLO | 162 | W 10-4 | 86-76 | 2 | 43,560 | Brett Myers | Ismael Valdez | Brett Myers | Ismael Valdez | | 840 | 781 | 59 |