| 2004-04-05 | @ SLN | 1 | W 8-6 | 1-0 | 2 | 49,149 | Ben Sheets | Matt Morris | Dave Burba | Matt Morris | Danny Kolb | 8 | 6 | 2 |
| 2004-04-06 | @ SLN | 2 | W 7-5 | 2-0 | 2 | 23,966 | Doug Davis | Jason Marquis | Doug Davis | Jason Marquis | Danny Kolb | 15 | 11 | 4 |
| 2004-04-07 | @ SLN | 3 | L 4-9 | 2-1 | 1 | 23,488 | Matt Kinney | Woody Williams | Mike Lincoln | Adrian Hernandez | | 19 | 20 | -1 |
| 2004-04-08 | @ SLN | 4 | W 11-5 | 3-1 | 1 | 27,433 | Chris Capuano | Jeff Suppan | Chris Capuano | Jeff Suppan | Dave Burba | 30 | 25 | 5 |
| 2004-04-09 | vs HOU | 5 | L 7-13 | 3-2 | 2 | 44,405 | Wes Obermueller | Wade Miller | Wade Miller | Wes Obermueller | | 37 | 38 | -1 |
| 2004-04-10 | vs HOU | 6 | W 6-1 | 4-2 | 2 | 18,337 | Ben Sheets | Tim Redding | Ben Sheets | Tim Redding | | 43 | 39 | 4 |
| 2004-04-11 | vs HOU | 7 | L 4-7 | 4-3 | 2 | 11,262 | Doug Davis | Roy Oswalt | Roy Oswalt | Doug Davis | | 47 | 46 | 1 |
| 2004-04-12 | @ SFN | 8 | L 5-7 | 4-4 | 4 | 42,548 | Matt Kinney | Jerome Williams | Jerome Williams | Matt Kinney | Matt Herges | 52 | 53 | -1 |
| 2004-04-13 | @ SFN | 9 | L 2-4 | 4-5 | 4 | 42,040 | Chris Capuano | Dustin Hermanson | Dustin Hermanson | Chris Capuano | Matt Herges | 54 | 57 | -3 |
| 2004-04-14 | @ SFN | 10 | W 3-0 | 5-5 | 4 | 37,844 | Wes Obermueller | Brian Cooper | Wes Obermueller | Brian Cooper | Danny Kolb | 57 | 57 | 0 |
| 2004-04-15 | @ HOU | 11 | W 6-2 | 6-5 | 4 | 33,010 | Ben Sheets | Tim Redding | Ben Sheets | Tim Redding | | 63 | 59 | 4 |
| 2004-04-16 | @ HOU | 12 | L 0-2 | 6-6 | 4 | 32,656 | Doug Davis | Roy Oswalt | Roy Oswalt | Doug Davis | | 63 | 61 | 2 |
| 2004-04-17 | @ HOU | 13 | L 5-14 | 6-7 | 6 | 40,030 | Matt Kinney | Brandon Duckworth | Brandon Backe | Matt Kinney | | 68 | 75 | -7 |
| 2004-04-18 | @ HOU | 14 | L 1-6 | 6-8 | 6 | 38,195 | Chris Capuano | Roger Clemens | Roger Clemens | Chris Capuano | | 69 | 81 | -12 |
| 2004-04-20 | vs ARI | 15 | W 4-2 | 7-8 | 6 | 10,244 | Ben Sheets | Elmer Dessens | Ben Sheets | Elmer Dessens | Danny Kolb | 73 | 83 | -10 |
| 2004-04-21 | vs ARI | 16 | W 10-6 | 8-8 | 5 | 11,223 | Doug Davis | Randy Johnson | Ben Ford | Randy Johnson | | 83 | 89 | -6 |
| 2004-04-22 | vs ARI | 17 | L 9-11 | 8-9 | 6 | 13,879 | Wes Obermueller | Brandon Webb | Steve Sparks | Adrian Hernandez | | 92 | 100 | -8 |
| 2004-04-23 | vs SLN | 18 | W 2-1 | 9-9 | 5 | 17,107 | Matt Kinney | Chris Carpenter | Brooks Kieschnick | Steve Kline | | 94 | 101 | -7 |
| 2004-04-24 | vs SLN | 19 | W 3-1 | 10-9 | 4 | 22,222 | Chris Saenz | Woody Williams | Chris Saenz | Woody Williams | Danny Kolb | 97 | 102 | -5 |
| 2004-04-25 | vs SLN | 20 | L 2-5 | 10-10 | 5 | 18,135 | Ben Sheets | Jeff Suppan | Jeff Suppan | Ben Sheets | | 99 | 107 | -8 |
| 2004-04-27 | vs CIN | 21 | W 9-8 | 11-10 | 4 | 8,918 | Doug Davis | Cory Lidle | Jeff Bennett | Danny Graves | | 108 | 115 | -7 |
| 2004-04-28 | vs CIN | 22 | W 10-9 | 12-10 | 4 | 9,103 | Matt Kinney | Paul Wilson | Dave Burba | Todd Van Poppel | | 118 | 124 | -6 |
| 2004-04-30 | vs PIT | 23 | L 2-4 | 12-11 | 4 | 17,533 | Ben Sheets | Kris Benson | Kris Benson | Ben Sheets | Jose Mesa | 120 | 128 | -8 |
| 2004-05-01 | vs PIT | 24 | L 7-8 | 12-12 | 4 | 25,134 | Wes Obermueller | Oliver Perez | Jason Boyd | Luis Vizcaino | Jose Mesa | 127 | 136 | -9 |
| 2004-05-02 | vs PIT | 25 | L 3-4 | 12-13 | 6 | 16,392 | Doug Davis | Ryan Vogelsong | Brian Meadows | Jeff Bennett | Jose Mesa | 130 | 140 | -10 |
| 2004-05-04 | @ CIN | 26 | W 6-2 | 13-13 | 5 | 14,228 | Victor Santos | Jimmy Haynes | Victor Santos | Jimmy Haynes | | 136 | 142 | -6 |
| 2004-05-05 | @ CIN | 27 | L 4-5 | 13-14 | 5 | 14,965 | Ben Sheets | Jose Acevedo | Danny Graves | Jeff Bennett | | 140 | 147 | -7 |
| 2004-05-06 | @ CIN | 28 | L 6-9 | 13-15 | 5 | 17,489 | Wes Obermueller | Aaron Harang | Todd Jones | Jeff Bennett | Danny Graves | 146 | 156 | -10 |
| 2004-05-07 | @ NYN | 29 | W 7-5 | 14-15 | 5 | 27,841 | Doug Davis | Tom Glavine | Doug Davis | Tom Glavine | | 153 | 161 | -8 |
| 2004-05-08 | @ NYN | 30 | W 6-4 | 15-15 | 4 | 29,212 | Adrian Hernandez | Tyler Yates | Matt Kinney | Tyler Yates | Danny Kolb | 159 | 165 | -6 |
| 2004-05-09 | @ NYN | 31 | L 5-6 | 15-16 | 5 | 29,686 | Victor Santos | Steve Trachsel | Dan Wheeler | Ben Ford | | 164 | 171 | -7 |
| 2004-05-11 | vs MON | 32 | W 8-5 | 16-16 | 5 | 10,761 | Ben Sheets | Livan Hernandez | Dave Burba | T.J. Tucker | | 172 | 176 | -4 |
| 2004-05-12 | vs MON | 33 | W 4-3 | 17-16 | 5 | 10,803 | Wes Obermueller | Zach Day | Wes Obermueller | Zach Day | Danny Kolb | 176 | 179 | -3 |
| 2004-05-13 | vs MON | 34 | W 7-4 | 18-16 | 3 | 14,972 | Doug Davis | Sun-Woo Kim | Doug Davis | Sun-Woo Kim | Danny Kolb | 183 | 183 | 0 |
| 2004-05-14 | vs ATL | 35 | L 0-2 | 18-17 | 5 | 33,061 | Victor Santos | Horacio Ramirez | Horacio Ramirez | Luis Vizcaino | John Smoltz | 183 | 185 | -2 |
| 2004-05-15 | vs ATL | 36 | L 6-11 | 18-18 | 5 | 26,862 | Matt Kinney | Russ Ortiz | Antonio Alfonseca | Matt Kinney | | 189 | 196 | -7 |
| 2004-05-16 | vs ATL | 37 | W 4-1 | 19-18 | 5 | 20,654 | Ben Sheets | Jaret Wright | Ben Sheets | Jaret Wright | | 193 | 197 | -4 |
| 2004-05-18 | @ MON | 38 | L 2-3 | 19-19 | 5 | 8,387 | Doug Davis | Zach Day | Zach Day | Doug Davis | Rocky Biddle | 195 | 200 | -5 |
| 2004-05-19 | @ MON | 39 | W 6-3 | 20-19 | 5 | 8,157 | Victor Santos | Sun-Woo Kim | Victor Santos | Sun-Woo Kim | Danny Kolb | 201 | 203 | -2 |
| 2004-05-20 | @ MON | 40 | W 3-2 | 21-19 | 5 | 8,941 | Matt Wise | Tomo Ohka | Mike Adams | Rocky Biddle | Danny Kolb | 204 | 205 | -1 |
| 2004-05-22 | @ PIT | 41 | L 1-3 | 21-20 | 5 | 25,736 | Ben Sheets | Josh Fogg | Josh Fogg | Ben Sheets | Jose Mesa | 205 | 208 | -3 |
| 2004-05-23 | @ PIT | 42 | W 2-1 | 22-20 | 4 | 19,326 | Doug Davis | Kip Wells | Luis Vizcaino | Brian Meadows | Danny Kolb | 207 | 209 | -2 |
| 2004-05-25 | vs LAN | 43 | L 3-5 | 22-21 | 5 | 16,129 | Victor Santos | Kazuhisa Ishii | Jose Lima | Victor Santos | Eric Gagne | 210 | 214 | -4 |
| 2004-05-26 | vs LAN | 44 | W 2-1 | 23-21 | 4 | 14,084 | Chris Capuano | Odalis Perez | Matt Kinney | Duaner Sanchez | | 212 | 215 | -3 |
| 2004-05-27 | vs LAN | 45 | W 3-1 | 24-21 | 4 | 24,616 | Ben Sheets | Jeff Weaver | Ben Sheets | Jeff Weaver | Danny Kolb | 215 | 216 | -1 |
| 2004-05-28 | vs SDN | 46 | L 3-5 | 24-22 | 5 | 17,851 | Doug Davis | Brian Lawrence | Brian Lawrence | Doug Davis | Trevor Hoffman | 218 | 221 | -3 |
| 2004-05-29 | vs SDN | 47 | W 4-3 | 25-22 | 4 | 29,499 | Wes Obermueller | Dennis Tankersley | Wes Obermueller | Dennis Tankersley | Danny Kolb | 222 | 224 | -2 |
| 2004-05-30 | vs SDN | 48 | L 2-5 | 25-23 | 5 | 27,168 | Victor Santos | Ismael Valdez | Ismael Valdez | Victor Santos | Trevor Hoffman | 224 | 229 | -5 |
| 2004-05-31 | @ LAN | 49 | L 2-3 | 25-24 | 5 | 32,642 | Matt Wise | Odalis Perez | Eric Gagne | Dave Burba | | 226 | 232 | -6 |
| 2004-06-01 | @ LAN | 50 | W 4-1 | 26-24 | 5 | 22,402 | Doug Davis | Jeff Weaver | Doug Davis | Jeff Weaver | Danny Kolb | 230 | 233 | -3 |
| 2004-06-02 | @ LAN | 51 | L 2-5 | 26-25 | 5 | 27,871 | Ben Hendrickson | Edwin Jackson | Edwin Jackson | Ben Hendrickson | Eric Gagne | 232 | 238 | -6 |
| 2004-06-04 | @ SDN | 52 | W 3-1 | 27-25 | 4 | 41,828 | Victor Santos | Dennis Tankersley | Victor Santos | Dennis Tankersley | Danny Kolb | 235 | 239 | -4 |
| 2004-06-05 | @ SDN | 53 | L 0-4 | 27-26 | 5 | 39,817 | Wes Obermueller | Ismael Valdez | Ismael Valdez | Wes Obermueller | | 235 | 243 | -8 |
| 2004-06-06 | @ SDN | 54 | L 3-8 | 27-27 | 5 | 40,348 | Doug Davis | Adam Eaton | Adam Eaton | Doug Davis | | 238 | 251 | -13 |
| 2004-06-08 | @ ANA | 55 | W 1-0 | 28-27 | 5 | 37,589 | Ben Sheets | Kelvim Escobar | Matt Kinney | Ramon Ortiz | Danny Kolb | 239 | 251 | -12 |
| 2004-06-09 | @ ANA | 56 | W 12-2 | 29-27 | 4 | 41,423 | Victor Santos | Jarrod Washburn | Victor Santos | Jarrod Washburn | Dave Burba | 251 | 253 | -2 |
| 2004-06-10 | @ ANA | 57 | L 4-5 | 29-28 | 5 | 39,425 | Wes Obermueller | Aaron Sele | Kevin Gregg | Jeff Bennett | Francisco Rodriguez | 255 | 258 | -3 |
| 2004-06-11 | vs HOU | 58 | W 9-3 | 30-28 | 4 | 26,141 | Doug Davis | Tim Redding | Doug Davis | Tim Redding | | 264 | 261 | 3 |
| 2004-06-12 | vs HOU | 59 | W 7-4 | 31-28 | 4 | 40,223 | Chris Capuano | Roy Oswalt | Chris Capuano | Roy Oswalt | Danny Kolb | 271 | 265 | 6 |
| 2004-06-13 | vs HOU | 60 | L 4-5 | 31-29 | 5 | 23,007 | Ben Sheets | Peter Munro | Dan Miceli | Ben Sheets | Octavio Dotel | 275 | 270 | 5 |
| 2004-06-15 | vs SEA | 61 | W 3-0 | 32-29 | 4 | 24,559 | Victor Santos | Freddy Garcia | Victor Santos | Freddy Garcia | Danny Kolb | 278 | 270 | 8 |
| 2004-06-16 | vs SEA | 62 | W 4-1 | 33-29 | 4 | 21,274 | Doug Davis | Clint Nageotte | Doug Davis | Clint Nageotte | Danny Kolb | 282 | 271 | 11 |
| 2004-06-17 | vs SEA | 63 | L 3-6 | 33-30 | 4 | 19,057 | Chris Capuano | Ryan Franklin | Mike Myers | Matt Kinney | Eddie Guardado | 285 | 277 | 8 |
| 2004-06-18 | vs MIN | 64 | W 4-1 | 34-30 | 4 | 28,555 | Ben Sheets | Carlos Silva | Ben Sheets | Carlos Silva | Danny Kolb | 289 | 278 | 11 |
| 2004-06-19 | vs MIN | 65 | W 7-6 | 35-30 | 4 | 36,882 | Wes Obermueller | Brad Radke | Luis Vizcaino | Terry Mulholland | Danny Kolb | 296 | 284 | 12 |
| 2004-06-20 | vs MIN | 66 | L 2-4 | 35-31 | 4 | 33,752 | Victor Santos | Johan Santana | Johan Santana | Victor Santos | Joe Nathan | 298 | 288 | 10 |
| 2004-06-22 | vs COL | 67 | W 6-2 | 36-31 | 4 | 13,264 | Doug Davis | Jason Jennings | Doug Davis | Javier Lopez | | 304 | 290 | 14 |
| 2004-06-23 | vs COL | 68 | L 2-3 | 36-32 | 4 | 19,964 | Chris Capuano | Shawn Estes | Shawn Estes | Chris Capuano | Shawn Chacon | 306 | 293 | 13 |
| 2004-06-24 | vs COL | 69 | L 0-3 | 36-33 | 5 | 21,224 | Ben Sheets | Aaron Cook | Aaron Cook | Ben Sheets | Shawn Chacon | 306 | 296 | 10 |
| 2004-06-25 | @ MIN | 70 | L 3-6 | 36-34 | 5 | 24,160 | Wes Obermueller | Johan Santana | Johan Santana | Wes Obermueller | Joe Nathan | 309 | 302 | 7 |
| 2004-06-26 | @ MIN | 71 | W 7-2 | 37-34 | 4 | 26,137 | Victor Santos | Matt Guerrier | Victor Santos | Matt Guerrier | | 316 | 304 | 12 |
| 2004-06-27 | @ MIN | 72 | W 7-3 | 38-34 | 4 | 25,398 | Doug Davis | Kyle Lohse | Doug Davis | Kyle Lohse | | 323 | 307 | 16 |
| 2004-06-29 | @ COL | 73 | W 6-3 | 39-34 | 4 | 28,085 | Chris Capuano | Shawn Estes | Chris Capuano | Shawn Estes | Danny Kolb | 329 | 310 | 19 |
| 2004-06-30 | @ COL | 74 | W 5-4 | 40-34 | 4 | 24,126 | Ben Sheets | Aaron Cook | Ben Sheets | Aaron Cook | Danny Kolb | 334 | 314 | 20 |
| 2004-07-01 | @ COL | 75 | W 10-9 | 41-34 | 3 | 24,360 | Victor Santos | Denny Stark | Victor Santos | Denny Stark | Danny Kolb | 344 | 323 | 21 |
| 2004-07-02 | @ PIT | 76 | L 1-8 | 41-36 | 3 | 0 | Doug Davis | Oliver Perez | Oliver Perez | Doug Davis | | 345 | 331 | 14 |
| 2004-07-02 | @ PIT | 77 | L 2-13 | 41-36 | 3 | 30,047 | Matt Wise | Josh Fogg | Josh Fogg | Matt Wise | | 347 | 344 | 3 |
| 2004-07-03 | @ PIT | 78 | L 3-5 | 41-37 | 4 | 28,443 | Wes Obermueller | Kris Benson | Kris Benson | Wes Obermueller | Jose Mesa | 350 | 349 | 1 |
| 2004-07-04 | @ PIT | 79 | L 2-6 | 41-38 | 4 | 19,029 | Chris Capuano | Sean Burnett | Sean Burnett | Chris Capuano | Jose Mesa | 352 | 355 | -3 |
| 2004-07-05 | vs CHN | 80 | W 1-0 | 42-38 | 4 | 45,016 | Ben Sheets | Matt Clement | Ben Sheets | Matt Clement | Danny Kolb | 353 | 355 | -2 |
| 2004-07-06 | vs CHN | 81 | W 4-2 | 43-38 | 3 | 42,295 | Victor Santos | Mark Prior | Victor Santos | Mark Prior | Danny Kolb | 357 | 357 | 0 |
| 2004-07-07 | vs CHN | 82 | W 4-0 | 44-38 | 3 | 42,291 | Doug Davis | Carlos Zambrano | Doug Davis | Carlos Zambrano | | 361 | 357 | 4 |
| 2004-07-08 | vs CIN | 83 | L 3-9 | 44-39 | 3 | 19,729 | Wes Obermueller | Paul Wilson | Paul Wilson | Wes Obermueller | | 364 | 366 | -2 |
| 2004-07-09 | vs CIN | 84 | L 0-3 | 44-40 | 4 | 30,709 | Chris Capuano | Aaron Harang | Aaron Harang | Chris Capuano | Danny Graves | 364 | 369 | -5 |
| 2004-07-10 | vs CIN | 85 | W 5-0 | 45-40 | 3 | 43,558 | Ben Sheets | Cory Lidle | Ben Sheets | Cory Lidle | | 369 | 369 | 0 |
| 2004-07-11 | vs CIN | 86 | L 6-9 | 45-41 | 4 | 31,841 | Victor Santos | Jose Acevedo | Todd Jones | Danny Kolb | Danny Graves | 375 | 378 | -3 |
| 2004-07-15 | @ CHN | 87 | L 1-4 | 45-42 | 4 | 40,123 | Doug Davis | Mark Prior | Glendon Rusch | Doug Davis | LaTroy Hawkins | 376 | 382 | -6 |
| 2004-07-16 | @ CHN | 88 | W 3-2 | 46-42 | 3 | 39,968 | Victor Santos | Matt Clement | Victor Santos | Matt Clement | Danny Kolb | 379 | 384 | -5 |
| 2004-07-17 | @ CHN | 89 | L 0-5 | 46-43 | 4 | 40,003 | Ben Sheets | Greg Maddux | Greg Maddux | Ben Sheets | | 379 | 389 | -10 |
| 2004-07-18 | @ CHN | 90 | W 4-2 | 47-43 | 3 | 39,911 | Chris Capuano | Kerry Wood | Chris Capuano | Francis Beltran | Danny Kolb | 383 | 391 | -8 |
| 2004-07-19 | @ CIN | 91 | L 4-8 | 47-44 | 4 | 25,793 | Ben Hendrickson | Aaron Harang | Aaron Harang | Ben Hendrickson | | 387 | 399 | -12 |
| 2004-07-20 | @ CIN | 92 | L 2-6 | 47-45 | 4 | 25,388 | Doug Davis | Brandon Claussen | Brandon Claussen | Doug Davis | | 389 | 405 | -16 |
| 2004-07-21 | @ SLN | 93 | L 0-1 | 47-46 | 4 | 37,104 | Victor Santos | Woody Williams | Woody Williams | Victor Santos | Jason Isringhausen | 389 | 406 | -17 |
| 2004-07-22 | @ SLN | 94 | L 0-4 | 47-47 | 4 | 35,100 | Ben Sheets | Jason Marquis | Jason Marquis | Ben Sheets | | 389 | 410 | -21 |
| 2004-07-23 | @ HOU | 95 | W 7-6 | 48-47 | 4 | 36,732 | Chris Capuano | Roger Clemens | Luis Vizcaino | Brad Lidge | Danny Kolb | 396 | 416 | -20 |
| 2004-07-24 | @ HOU | 96 | L 3-6 | 48-48 | 4 | 40,334 | Ben Hendrickson | Tim Redding | Tim Redding | Ben Hendrickson | Brad Lidge | 399 | 422 | -23 |
| 2004-07-25 | @ HOU | 97 | L 1-9 | 48-49 | 5 | 32,971 | Doug Davis | Peter Munro | Peter Munro | Doug Davis | | 400 | 431 | -31 |
| 2004-07-26 | vs CHN | 98 | L 1-3 | 48-50 | 5 | 41,585 | Victor Santos | Matt Clement | Matt Clement | Victor Santos | LaTroy Hawkins | 401 | 434 | -33 |
| 2004-07-27 | vs CHN | 99 | L 1-7 | 48-51 | 6 | 41,520 | Ben Sheets | Greg Maddux | Greg Maddux | Ben Sheets | | 402 | 441 | -39 |
| 2004-07-28 | vs CHN | 100 | W 6-3 | 49-51 | 5 | 41,588 | Chris Capuano | Kerry Wood | Chris Capuano | Kerry Wood | Danny Kolb | 408 | 444 | -36 |
| 2004-07-29 | vs CHN | 101 | L 0-4 | 49-52 | 5 | 42,443 | Ben Hendrickson | Carlos Zambrano | Carlos Zambrano | Ben Hendrickson | | 408 | 448 | -40 |
| 2004-07-30 | vs PIT | 102 | W 5-0 | 50-52 | 5 | 34,702 | Doug Davis | Sean Burnett | Doug Davis | Sean Burnett | | 413 | 448 | -35 |
| 2004-07-31 | vs PIT | 103 | L 1-4 | 50-53 | 5 | 35,152 | Victor Santos | Ryan Vogelsong | Ryan Vogelsong | Victor Santos | Jose Mesa | 414 | 452 | -38 |
| 2004-08-01 | vs PIT | 104 | W 8-7 | 51-53 | 4 | 25,047 | Ben Sheets | Kip Wells | Luis Vizcaino | Brian Meadows | | 422 | 459 | -37 |
| 2004-08-03 | vs NYN | 105 | L 3-12 | 51-54 | 4 | 22,306 | Chris Capuano | Al Leiter | Al Leiter | Chris Capuano | | 425 | 471 | -46 |
| 2004-08-04 | vs NYN | 106 | L 5-6 | 51-55 | 5 | 18,196 | Doug Davis | Steve Trachsel | Pedro Feliciano | Mike Adams | Braden Looper | 430 | 477 | -47 |
| 2004-08-05 | vs NYN | 107 | L 6-11 | 51-56 | 5 | 32,225 | Victor Santos | Victor Zambrano | Victor Zambrano | Victor Santos | | 436 | 488 | -52 |
| 2004-08-06 | @ FLO | 108 | L 6-7 | 51-57 | 5 | 21,484 | Ben Sheets | A.J. Burnett | Billy Koch | Danny Kolb | | 442 | 495 | -53 |
| 2004-08-07 | @ FLO | 109 | L 0-5 | 51-58 | 5 | 22,816 | Wes Obermueller | Ismael Valdez | Ismael Valdez | Wes Obermueller | | 442 | 500 | -58 |
| 2004-08-08 | @ FLO | 110 | W 2-0 | 52-58 | 5 | 25,877 | Chris Capuano | Dontrelle Willis | Chris Capuano | Dontrelle Willis | Danny Kolb | 444 | 500 | -56 |
| 2004-08-10 | @ ATL | 111 | W 3-2 | 53-58 | 5 | 21,681 | Doug Davis | John Thomson | Mike Adams | Tom Martin | Danny Kolb | 447 | 502 | -55 |
| 2004-08-11 | @ ATL | 112 | L 3-10 | 53-59 | 6 | 21,673 | Victor Santos | Mike Hampton | Mike Hampton | Victor Santos | | 450 | 512 | -62 |
| 2004-08-12 | @ ATL | 113 | L 2-4 | 53-60 | 6 | 21,013 | Ben Sheets | Jaret Wright | Jaret Wright | Ben Sheets | John Smoltz | 452 | 516 | -64 |
| 2004-08-13 | vs FLO | 114 | W 6-4 | 54-60 | 5 | 35,544 | Wes Obermueller | Ismael Valdez | Wes Obermueller | Ismael Valdez | Danny Kolb | 458 | 520 | -62 |
| 2004-08-14 | vs FLO | 115 | L 1-11 | 54-61 | 6 | 40,213 | Jorge de la Rosa | Dontrelle Willis | Dontrelle Willis | Jorge de la Rosa | | 459 | 531 | -72 |
| 2004-08-15 | vs FLO | 116 | L 3-5 | 54-62 | 6 | 27,205 | Doug Davis | Josh Beckett | Rudy Seanez | Ben Hendrickson | Armando Benitez | 462 | 536 | -74 |
| 2004-08-17 | vs CHN | 117 | W 3-1 | 55-62 | 6 | 41,174 | Victor Santos | Carlos Zambrano | Victor Santos | Carlos Zambrano | Danny Kolb | 465 | 537 | -72 |
| 2004-08-18 | vs CHN | 118 | L 5-7 | 55-63 | 6 | 41,441 | Ben Sheets | Matt Clement | Kent Mercker | Travis Phelps | LaTroy Hawkins | 470 | 544 | -74 |
| 2004-08-19 | vs CHN | 119 | L 6-9 | 55-64 | 6 | 42,406 | Chris Capuano | Greg Maddux | Greg Maddux | Chris Capuano | LaTroy Hawkins | 476 | 553 | -77 |
| 2004-08-20 | vs PHI | 120 | L 2-4 | 55-65 | 6 | 22,559 | Doug Davis | Eric Milton | Eric Milton | Doug Davis | Tim Worrell | 478 | 557 | -79 |
| 2004-08-21 | vs PHI | 121 | L 6-8 | 55-66 | 6 | 30,841 | Wes Obermueller | Vicente Padilla | Geoff Geary | Luis Vizcaino | Tim Worrell | 484 | 565 | -81 |
| 2004-08-22 | vs PHI | 122 | L 6-9 | 55-67 | 6 | 32,411 | Victor Santos | Randy Wolf | Felix Rodriguez | Danny Kolb | Tim Worrell | 490 | 574 | -84 |
| 2004-08-23 | @ CHN | 123 | L 3-8 | 55-68 | 6 | 38,925 | Ben Sheets | Carlos Zambrano | Carlos Zambrano | Ben Sheets | | 493 | 582 | -89 |
| 2004-08-24 | @ CHN | 124 | L 4-13 | 55-69 | 6 | 38,457 | Chris Capuano | Matt Clement | Matt Clement | Chris Capuano | Glendon Rusch | 497 | 595 | -98 |
| 2004-08-25 | @ CHN | 125 | L 2-4 | 55-70 | 6 | 38,365 | Doug Davis | Greg Maddux | LaTroy Hawkins | Luis Vizcaino | | 499 | 599 | -100 |
| 2004-08-27 | @ PHI | 126 | L 1-6 | 55-71 | 6 | 40,367 | Victor Santos | Vicente Padilla | Vicente Padilla | Victor Santos | | 500 | 605 | -105 |
| 2004-08-28 | @ PHI | 127 | L 3-4 | 55-72 | 6 | 43,267 | Ben Sheets | Randy Wolf | Tim Worrell | Mike Adams | | 503 | 609 | -106 |
| 2004-08-29 | @ PHI | 128 | L 0-10 | 55-73 | 6 | 43,339 | Wes Obermueller | Cory Lidle | Cory Lidle | Wes Obermueller | | 503 | 619 | -116 |
| 2004-08-30 | vs PIT | 129 | L 1-5 | 55-74 | 6 | 23,512 | Ben Hendrickson | Josh Fogg | Josh Fogg | Ben Hendrickson | | 504 | 624 | -120 |
| 2004-08-31 | vs PIT | 130 | W 4-2 | 56-74 | 6 | 13,704 | Doug Davis | John Van Benschoten | Matt Wise | John Van Benschoten | Danny Kolb | 508 | 626 | -118 |
| 2004-09-01 | vs PIT | 131 | L 2-5 | 56-75 | 6 | 15,625 | Victor Santos | Ryan Vogelsong | Salomon Torres | Jeff Bennett | Jose Mesa | 510 | 631 | -121 |
| 2004-09-02 | vs PIT | 132 | W 7-1 | 57-75 | 6 | 11,763 | Ben Sheets | David Williams | Ben Sheets | David Williams | | 517 | 632 | -115 |
| 2004-09-03 | vs CIN | 133 | W 11-4 | 58-75 | 6 | 16,262 | Wes Obermueller | Brandon Claussen | Wes Obermueller | Brandon Claussen | | 528 | 636 | -108 |
| 2004-09-04 | vs CIN | 134 | W 7-3 | 59-75 | 6 | 26,059 | Ben Hendrickson | Josh Hancock | Ben Hendrickson | Josh Hancock | Danny Kolb | 535 | 639 | -104 |
| 2004-09-05 | vs CIN | 135 | L 2-9 | 59-76 | 6 | 33,446 | Jorge de la Rosa | Luke Hudson | Luke Hudson | Jorge de la Rosa | | 537 | 648 | -111 |
| 2004-09-06 | @ PIT | 136 | W 9-5 | 60-76 | 6 | 12,771 | Gary Glover | Ryan Vogelsong | Gary Glover | Ryan Vogelsong | Danny Kolb | 546 | 653 | -107 |
| 2004-09-07 | @ PIT | 137 | L 0-2 | 60-77 | 6 | 20,563 | Ben Sheets | David Williams | David Williams | Ben Sheets | Jose Mesa | 546 | 655 | -109 |
| 2004-09-09 | @ CIN | 138 | W 7-2 | 61-77 | 6 | 15,011 | Doug Davis | Brandon Claussen | Doug Davis | Gabe White | | 553 | 657 | -104 |
| 2004-09-10 | @ CIN | 139 | L 4-6 | 61-78 | 6 | 19,146 | Ben Hendrickson | Josh Hancock | Josh Hancock | Ben Hendrickson | Danny Graves | 557 | 663 | -106 |
| 2004-09-11 | @ CIN | 140 | L 0-9 | 61-79 | 6 | 22,863 | Victor Santos | Luke Hudson | Luke Hudson | Victor Santos | | 557 | 672 | -115 |
| 2004-09-12 | @ CIN | 141 | W 11-0 | 62-79 | 6 | 17,236 | Ben Sheets | Aaron Harang | Ben Sheets | Aaron Harang | | 568 | 672 | -104 |
| 2004-09-14 | vs SFN | 142 | L 2-3 | 62-80 | 6 | 27,209 | Doug Davis | Kirk Rueter | Kirk Rueter | Doug Davis | Dustin Hermanson | 570 | 675 | -105 |
| 2004-09-15 | vs SFN | 143 | L 1-8 | 62-81 | 6 | 22,228 | Wes Obermueller | Brett Tomko | Brett Tomko | Wes Obermueller | | 571 | 683 | -112 |
| 2004-09-16 | vs SFN | 144 | L 0-4 | 62-82 | 6 | 17,574 | Victor Santos | Brad Hennessey | Brad Hennessey | Victor Santos | | 571 | 687 | -116 |
| 2004-09-17 | @ HOU | 145 | L 1-2 | 62-83 | 6 | 38,839 | Ben Sheets | Roy Oswalt | Roy Oswalt | Ben Sheets | Brad Lidge | 572 | 689 | -117 |
| 2004-09-18 | @ HOU | 146 | L 3-4 | 62-84 | 6 | 40,408 | Gary Glover | Peter Munro | Chad Harville | Gary Glover | Brad Lidge | 575 | 693 | -118 |
| 2004-09-19 | @ HOU | 147 | L 0-1 | 62-85 | 6 | 35,678 | Doug Davis | Roger Clemens | Roger Clemens | Doug Davis | Brad Lidge | 575 | 694 | -119 |
| 2004-09-20 | vs SLN | 148 | L 4-7 | 62-86 | 6 | 14,213 | Jorge de la Rosa | Matt Morris | Julian Tavarez | Danny Kolb | Jason Isringhausen | 579 | 701 | -122 |
| 2004-09-21 | vs SLN | 149 | W 6-4 | 63-86 | 6 | 25,675 | Victor Santos | Jason Marquis | Victor Santos | Jason Marquis | Danny Kolb | 585 | 705 | -120 |
| 2004-09-22 | vs SLN | 150 | L 2-3 | 63-87 | 6 | 21,461 | Ben Sheets | Woody Williams | Woody Williams | Ben Sheets | Jason Isringhausen | 587 | 708 | -121 |
| 2004-09-23 | vs SLN | 151 | L 2-4 | 63-88 | 6 | 15,200 | Ben Hendrickson | Dan Haren | Cal Eldred | Matt Wise | Jason Isringhausen | 589 | 712 | -123 |
| 2004-09-24 | vs HOU | 152 | L 0-1 | 63-89 | 6 | 34,890 | Doug Davis | Roger Clemens | Brad Lidge | Mike Adams | Dan Miceli | 589 | 713 | -124 |
| 2004-09-25 | vs HOU | 153 | W 8-0 | 64-89 | 6 | 22,812 | Wes Obermueller | Peter Munro | Wes Obermueller | Peter Munro | | 597 | 713 | -116 |
| 2004-09-26 | vs HOU | 154 | L 7-11 | 64-90 | 6 | 18,496 | Victor Santos | Carlos Hernandez | Tim Redding | Victor Santos | | 604 | 724 | -120 |
| 2004-09-27 | @ ARI | 155 | L 1-3 | 64-91 | 6 | 25,123 | Ben Sheets | Randy Johnson | Randy Johnson | Ben Sheets | Greg Aquino | 605 | 727 | -122 |
| 2004-09-28 | @ ARI | 156 | L 8-9 | 64-92 | 6 | 23,936 | Jorge de la Rosa | Brandon Webb | Mike Koplove | Brooks Kieschnick | | 613 | 736 | -123 |
| 2004-09-29 | @ ARI | 157 | W 4-1 | 65-92 | 6 | 21,710 | Gary Glover | Casey Fossum | Gary Glover | Casey Fossum | Luis Vizcaino | 617 | 737 | -120 |
| 2004-09-30 | @ SLN | 158 | W 7-6 | 66-92 | 6 | 24,893 | Doug Davis | Matt Morris | Doug Davis | Matt Morris | Danny Kolb | 624 | 743 | -119 |
| 2004-10-01 | @ SLN | 159 | L 1-4 | 66-93 | 6 | 32,605 | Ben Hendrickson | Alberto Reyes | Rick Ankiel | Ben Hendrickson | Jason Isringhausen | 625 | 747 | -122 |
| 2004-10-02 | @ SLN | 160 | W 5-1 | 67-93 | 6 | 41,219 | Ben Sheets | Jason Marquis | Ben Sheets | Jason Marquis | | 630 | 748 | -118 |
| 2004-10-03 | @ SLN | 161 | L 4-9 | 67-94 | 6 | 39,849 | Jorge de la Rosa | Randy Flores | Kiko Calero | Jorge de la Rosa | | 634 | 757 | -123 |