| 2003-03-31 | vs NYA | 1 | L 4-8 | 0-1 | 5 | 50,119 | Roy Halladay | Roger Clemens | Roger Clemens | Roy Halladay | | 4 | 8 | -4 |
| 2003-04-01 | vs NYA | 2 | L 1-10 | 0-2 | 5 | 15,176 | Cory Lidle | Andy Pettitte | Andy Pettitte | Cory Lidle | | 5 | 18 | -13 |
| 2003-04-02 | vs NYA | 3 | L 7-9 | 0-3 | 5 | 16,222 | Mark Hendrickson | Mike Mussina | Mike Mussina | Mark Hendrickson | Juan Acevedo | 12 | 27 | -15 |
| 2003-04-04 | @ MIN | 4 | W 7-2 | 1-3 | 4 | 48,617 | Tanyon Sturtze | Rick Reed | Tanyon Sturtze | Rick Reed | | 19 | 29 | -10 |
| 2003-04-05 | @ MIN | 5 | W 4-3 | 2-3 | 4 | 31,421 | Roy Halladay | Kenny Rogers | Pete Walker | Eddie Guardado | Kelvim Escobar | 23 | 32 | -9 |
| 2003-04-06 | @ MIN | 6 | W 8-1 | 3-3 | 3 | 23,549 | Cory Lidle | Brad Radke | Cory Lidle | Brad Radke | | 31 | 33 | -2 |
| 2003-04-08 | vs BOS | 7 | W 8-4 | 4-3 | 3 | 13,147 | Mark Hendrickson | Derek Lowe | Mark Hendrickson | Derek Lowe | | 39 | 37 | 2 |
| 2003-04-09 | vs BOS | 8 | W 10-5 | 5-3 | 2 | 13,099 | Tanyon Sturtze | Casey Fossum | Tanyon Sturtze | Casey Fossum | | 49 | 42 | 7 |
| 2003-04-10 | vs BOS | 9 | L 7-8 | 5-4 | 3 | 13,779 | Roy Halladay | John Burkett | Mike Timlin | Cliff Politte | | 56 | 50 | 6 |
| 2003-04-11 | vs MIN | 10 | L 4-6 | 5-5 | 3 | 13,237 | Cory Lidle | Kenny Rogers | Kenny Rogers | Cory Lidle | Eddie Guardado | 60 | 56 | 4 |
| 2003-04-12 | vs MIN | 11 | L 6-9 | 5-6 | 3 | 14,118 | Pete Walker | Brad Radke | LaTroy Hawkins | Kelvim Escobar | Eddie Guardado | 66 | 65 | 1 |
| 2003-04-13 | vs MIN | 12 | L 3-9 | 5-7 | 4 | 13,333 | Mark Hendrickson | Joe Mays | Joe Mays | Mark Hendrickson | | 69 | 74 | -5 |
| 2003-04-14 | @ NYA | 13 | L 9-10 | 5-8 | 4 | 30,761 | Tanyon Sturtze | Andy Pettitte | Jose Contreras | Aquilino Lopez | Chris Hammond | 78 | 84 | -6 |
| 2003-04-15 | @ NYA | 14 | L 0-5 | 5-9 | 4 | 33,833 | Roy Halladay | Mike Mussina | Mike Mussina | Roy Halladay | | 78 | 89 | -11 |
| 2003-04-16 | @ NYA | 15 | W 7-6 | 6-9 | 3 | 25,831 | Cory Lidle | David Wells | Cory Lidle | Sterling Hitchcock | Kelvim Escobar | 85 | 95 | -10 |
| 2003-04-17 | @ NYA | 16 | L 0-4 | 6-10 | 4 | 32,057 | Pete Walker | Jeff Weaver | Jeff Weaver | Pete Walker | | 85 | 99 | -14 |
| 2003-04-18 | @ BOS | 17 | L 3-7 | 6-11 | 4 | 31,440 | Mark Hendrickson | Tim Wakefield | Tim Wakefield | Jeff Tam | | 88 | 106 | -18 |
| 2003-04-19 | @ BOS | 18 | L 2-7 | 6-12 | 5 | 32,329 | Tanyon Sturtze | Derek Lowe | Derek Lowe | Tanyon Sturtze | | 90 | 113 | -23 |
| 2003-04-20 | @ BOS | 19 | L 5-6 | 6-13 | 5 | 29,579 | Roy Halladay | Casey Fossum | Mike Timlin | Cliff Politte | | 95 | 119 | -24 |
| 2003-04-21 | @ BOS | 20 | W 11-6 | 7-13 | 4 | 34,370 | Cory Lidle | John Burkett | Cory Lidle | John Burkett | | 106 | 125 | -19 |
| 2003-04-22 | @ TBA | 21 | L 3-4 | 7-14 | 5 | 10,013 | Pete Walker | Joe Kennedy | Joe Kennedy | Jason Kershner | Lance Carter | 109 | 129 | -20 |
| 2003-04-23 | @ TBA | 22 | L 3-4 | 7-15 | 5 | 9,221 | Mark Hendrickson | Victor Zambrano | Mike Venafro | Mark Hendrickson | Lance Carter | 112 | 133 | -21 |
| 2003-04-24 | @ TBA | 23 | W 5-3 | 8-15 | 5 | 8,618 | Tanyon Sturtze | Jorge Sosa | Tanyon Sturtze | Jorge Sosa | Kelvim Escobar | 117 | 136 | -19 |
| 2003-04-25 | vs KCA | 24 | W 6-5 | 9-15 | 5 | 16,417 | Roy Halladay | Darrell May | Kelvim Escobar | D.J. Carrasco | | 123 | 141 | -18 |
| 2003-04-26 | vs KCA | 25 | L 6-9 | 9-16 | 5 | 17,197 | Cory Lidle | Miguel Asencio | Jason Grimsley | Jeff Tam | Mike MacDougal | 129 | 150 | -21 |
| 2003-04-27 | vs KCA | 26 | W 10-9 | 10-16 | 5 | 17,059 | Pete Walker | Runelvys Hernandez | Cliff Politte | Mike MacDougal | | 139 | 159 | -20 |
| 2003-04-29 | vs TEX | 27 | L 11-16 | 10-17 | 5 | 48,097 | Mark Hendrickson | John Thomson | John Thomson | Mark Hendrickson | Francisco Cordero | 150 | 175 | -25 |
| 2003-04-30 | vs TEX | 28 | L 3-11 | 10-18 | 5 | 16,021 | Tanyon Sturtze | Ryan Drese | Ryan Drese | Tanyon Sturtze | | 153 | 186 | -33 |
| 2003-05-01 | vs TEX | 29 | W 7-6 | 11-18 | 4 | 16,111 | Roy Halladay | Colby Lewis | Roy Halladay | Colby Lewis | Cliff Politte | 160 | 192 | -32 |
| 2003-05-02 | vs ANA | 30 | W 3-1 | 12-18 | 4 | 17,799 | Cory Lidle | John Lackey | Cory Lidle | John Lackey | | 163 | 193 | -30 |
| 2003-05-03 | vs ANA | 31 | W 7-1 | 13-18 | 4 | 21,007 | Doug Davis | Scot Shields | Doug Davis | Scot Shields | | 170 | 194 | -24 |
| 2003-05-04 | vs ANA | 32 | W 8-2 | 14-18 | 4 | 21,513 | Mark Hendrickson | Ramon Ortiz | Mark Hendrickson | Ramon Ortiz | Kelvim Escobar | 178 | 196 | -18 |
| 2003-05-06 | @ TEX | 33 | W 15-5 | 15-18 | 4 | 20,092 | Roy Halladay | Colby Lewis | Roy Halladay | Colby Lewis | | 193 | 201 | -8 |
| 2003-05-07 | @ TEX | 34 | L 4-5 | 15-19 | 4 | 18,508 | Tanyon Sturtze | Joaquin Benoit | Aaron Fultz | Tanyon Sturtze | Ugueth Urbina | 197 | 206 | -9 |
| 2003-05-08 | @ TEX | 35 | W 8-6 | 16-19 | 4 | 20,177 | Cory Lidle | Ryan Drese | Cory Lidle | Ryan Drese | Cliff Politte | 205 | 212 | -7 |
| 2003-05-09 | @ ANA | 36 | L 1-6 | 16-20 | 4 | 42,820 | Doug Davis | Aaron Sele | Aaron Sele | Doug Davis | | 206 | 218 | -12 |
| 2003-05-10 | @ ANA | 37 | W 7-4 | 17-20 | 4 | 43,661 | Mark Hendrickson | Ramon Ortiz | Mark Hendrickson | Ramon Ortiz | | 213 | 222 | -9 |
| 2003-05-11 | @ ANA | 38 | W 4-2 | 18-20 | 4 | 32,129 | Roy Halladay | Jarrod Washburn | Roy Halladay | Jarrod Washburn | Cliff Politte | 217 | 224 | -7 |
| 2003-05-13 | vs TBA | 39 | L 5-7 | 18-21 | 4 | 14,007 | Tanyon Sturtze | Joe Kennedy | Joe Kennedy | Tanyon Sturtze | Lance Carter | 222 | 231 | -9 |
| 2003-05-14 | vs TBA | 40 | W 7-6 | 19-21 | 3 | 29,013 | Cory Lidle | Dewon Brazelton | Cory Lidle | Dewon Brazelton | Cliff Politte | 229 | 237 | -8 |
| 2003-05-15 | vs TBA | 41 | L 5-9 | 19-22 | 3 | 20,417 | Doug Davis | Jim Parque | Jesus Colome | Doug Davis | | 234 | 246 | -12 |
| 2003-05-16 | @ KCA | 42 | W 18-1 | 20-22 | 3 | 24,167 | Mark Hendrickson | Chris George | Mark Hendrickson | Chris George | | 252 | 247 | 5 |
| 2003-05-17 | @ KCA | 43 | W 7-4 | 21-22 | 3 | 25,032 | Roy Halladay | Jeremy Affeldt | Roy Halladay | Jason Grimsley | Cliff Politte | 259 | 251 | 8 |
| 2003-05-18 | @ KCA | 44 | W 4-3 | 22-22 | 3 | 15,462 | Kelvim Escobar | Kyle Snyder | Tanyon Sturtze | Kyle Snyder | Cliff Politte | 263 | 254 | 9 |
| 2003-05-19 | @ CHA | 45 | W 12-2 | 23-22 | 3 | 19,628 | Cory Lidle | Dan Wright | Cory Lidle | Dan Wright | | 275 | 256 | 19 |
| 2003-05-20 | @ CHA | 46 | L 1-4 | 23-23 | 3 | 12,857 | Doug Davis | Bartolo Colon | Bartolo Colon | Doug Davis | | 276 | 260 | 16 |
| 2003-05-21 | @ CHA | 47 | L 5-6 | 23-24 | 3 | 13,076 | Mark Hendrickson | Mark Buehrle | Damaso Marte | Cliff Politte | Billy Koch | 281 | 266 | 15 |
| 2003-05-22 | @ NYA | 48 | W 8-3 | 24-24 | 3 | 45,777 | Roy Halladay | Andy Pettitte | Roy Halladay | Andy Pettitte | | 289 | 269 | 20 |
| 2003-05-23 | @ NYA | 49 | W 6-2 | 25-24 | 3 | 34,134 | Kelvim Escobar | Mike Mussina | Kelvim Escobar | Mike Mussina | | 295 | 271 | 24 |
| 2003-05-24 | @ NYA | 50 | W 5-2 | 26-24 | 3 | 35,023 | Cory Lidle | David Wells | Cory Lidle | David Wells | Cliff Politte | 300 | 273 | 27 |
| 2003-05-25 | @ NYA | 51 | W 5-3 | 27-24 | 3 | 40,940 | Doug Davis | Jeff Weaver | Doug Davis | Jeff Weaver | Cliff Politte | 305 | 276 | 29 |
| 2003-05-26 | vs CHA | 52 | W 11-5 | 28-24 | 3 | 19,009 | Mark Hendrickson | Mark Buehrle | Josh Towers | Mark Buehrle | Jeff Tam | 316 | 281 | 35 |
| 2003-05-27 | vs CHA | 53 | W 5-1 | 29-24 | 3 | 19,365 | Roy Halladay | Bartolo Colon | Roy Halladay | Bartolo Colon | | 321 | 282 | 39 |
| 2003-05-28 | vs CHA | 54 | L 0-8 | 29-25 | 3 | 36,806 | Kelvim Escobar | Jon Garland | Jon Garland | Kelvim Escobar | | 321 | 290 | 31 |
| 2003-05-29 | vs CHA | 55 | L 2-3 | 29-26 | 3 | 20,010 | Cory Lidle | Esteban Loaiza | Esteban Loaiza | Cory Lidle | Billy Koch | 323 | 293 | 30 |
| 2003-05-30 | vs BOS | 56 | W 13-2 | 30-26 | 3 | 21,381 | Doug Davis | John Burkett | Doug Davis | John Burkett | | 336 | 295 | 41 |
| 2003-05-31 | vs BOS | 57 | W 10-7 | 31-26 | 3 | 28,809 | Mark Hendrickson | Casey Fossum | Tanyon Sturtze | Casey Fossum | Cliff Politte | 346 | 302 | 44 |
| 2003-06-01 | vs BOS | 58 | W 11-8 | 32-26 | 3 | 26,890 | Roy Halladay | Tim Wakefield | Roy Halladay | Matt White | | 357 | 310 | 47 |
| 2003-06-03 | @ SLN | 59 | L 5-11 | 32-27 | 3 | 28,907 | Kelvim Escobar | Matt Morris | Matt Morris | Kelvim Escobar | | 362 | 321 | 41 |
| 2003-06-04 | @ SLN | 60 | L 5-8 | 32-28 | 3 | 28,840 | Cory Lidle | Jason Simontacchi | Jason Simontacchi | Cory Lidle | Cal Eldred | 367 | 329 | 38 |
| 2003-06-05 | @ SLN | 61 | L 5-13 | 32-29 | 3 | 33,729 | Mark Hendrickson | Woody Williams | Woody Williams | Mark Hendrickson | | 372 | 342 | 30 |
| 2003-06-06 | @ CIN | 62 | W 9-2 | 33-29 | 3 | 28,281 | Roy Halladay | John Riedling | Roy Halladay | John Riedling | | 381 | 344 | 37 |
| 2003-06-07 | @ CIN | 63 | L 8-9 | 33-30 | 3 | 30,158 | Doug Davis | Ryan Dempster | Chris Reitsma | Cliff Politte | | 389 | 353 | 36 |
| 2003-06-08 | @ CIN | 64 | W 5-0 | 34-30 | 3 | 25,633 | Kelvim Escobar | Jimmy Haynes | Kelvim Escobar | Jimmy Haynes | | 394 | 353 | 41 |
| 2003-06-10 | vs PIT | 65 | W 13-8 | 35-30 | 3 | 14,090 | Cory Lidle | Kris Benson | Cory Lidle | Kris Benson | | 407 | 361 | 46 |
| 2003-06-11 | vs PIT | 66 | W 8-5 | 36-30 | 3 | 32,036 | Roy Halladay | Jeff D'Amico | Roy Halladay | Jeff D'Amico | | 415 | 366 | 49 |
| 2003-06-12 | vs PIT | 67 | W 5-4 | 37-30 | 3 | 15,015 | Mark Hendrickson | Jeff Suppan | Mark Hendrickson | Jeff Suppan | Cliff Politte | 420 | 370 | 50 |
| 2003-06-13 | vs CHN | 68 | W 5-1 | 38-30 | 3 | 23,018 | Kelvim Escobar | Kerry Wood | Kelvim Escobar | Kerry Wood | | 425 | 371 | 54 |
| 2003-06-14 | vs CHN | 69 | L 2-4 | 38-31 | 3 | 33,167 | Doug Davis | Mark Prior | Mark Prior | Doug Davis | Joe Borowski | 427 | 375 | 52 |
| 2003-06-15 | vs CHN | 70 | W 5-4 | 39-31 | 3 | 34,221 | Cory Lidle | Shawn Estes | Aquilino Lopez | Mark Guthrie | | 432 | 379 | 53 |
| 2003-06-18 | @ BAL | 71 | W 6-2 | 40-31 | 3 | 28,828 | Roy Halladay | Omar Daal | Roy Halladay | Omar Daal | Aquilino Lopez | 438 | 381 | 57 |
| 2003-06-19 | @ BAL | 72 | W 6-1 | 41-31 | 3 | 24,218 | Kelvim Escobar | Rick Helling | Kelvim Escobar | Rick Helling | | 444 | 382 | 62 |
| 2003-06-20 | @ MON | 73 | W 8-4 | 42-31 | 3 | 11,355 | Cory Lidle | Javier Vazquez | Cory Lidle | Javier Vazquez | | 452 | 386 | 66 |
| 2003-06-21 | @ MON | 74 | L 5-8 | 42-32 | 3 | 11,483 | Mark Hendrickson | Sun-Woo Kim | Luis Ayala | Cliff Politte | Rocky Biddle | 457 | 394 | 63 |
| 2003-06-22 | @ MON | 75 | W 4-2 | 43-32 | 2 | 15,508 | Roy Halladay | Livan Hernandez | Roy Halladay | Livan Hernandez | Cliff Politte | 461 | 396 | 65 |
| 2003-06-23 | vs BAL | 76 | W 13-4 | 44-32 | 2 | 17,555 | Doug Davis | Omar Daal | Doug Davis | Omar Daal | | 474 | 400 | 74 |
| 2003-06-24 | vs BAL | 77 | L 4-6 | 44-33 | 3 | 17,425 | Kelvim Escobar | Rick Helling | Rick Helling | Kelvim Escobar | Jorge Julio | 478 | 406 | 72 |
| 2003-06-25 | vs BAL | 78 | L 2-9 | 44-34 | 3 | 37,248 | Cory Lidle | Sidney Ponson | Sidney Ponson | Cory Lidle | | 480 | 415 | 65 |
| 2003-06-26 | vs BAL | 79 | W 13-8 | 45-34 | 3 | 19,098 | Mark Hendrickson | Rodrigo Lopez | Tanyon Sturtze | Travis Driskill | Aquilino Lopez | 493 | 423 | 70 |
| 2003-06-27 | vs MON | 80 | W 6-5 | 46-34 | 3 | 24,024 | Roy Halladay | Livan Hernandez | Trever Miller | Julio Manon | | 499 | 428 | 71 |
| 2003-06-28 | vs MON | 81 | L 2-4 | 46-35 | 3 | 33,334 | Doug Davis | Claudio Vargas | Claudio Vargas | Doug Davis | Rocky Biddle | 501 | 432 | 69 |
| 2003-06-29 | vs MON | 82 | L 2-10 | 46-36 | 3 | 37,354 | Kelvim Escobar | Tomo Ohka | Tomo Ohka | Kelvim Escobar | | 503 | 442 | 61 |
| 2003-06-30 | @ DET | 83 | L 2-6 | 46-37 | 3 | 13,353 | Cory Lidle | Mike Maroth | Mike Maroth | Cory Lidle | | 505 | 448 | 57 |
| 2003-07-01 | @ DET | 84 | L 0-5 | 46-38 | 3 | 15,448 | Mark Hendrickson | Matt Roney | Matt Roney | Mark Hendrickson | Jamie Walker | 505 | 453 | 52 |
| 2003-07-02 | @ DET | 85 | W 8-2 | 47-38 | 3 | 16,052 | Roy Halladay | Adam Bernero | Roy Halladay | Adam Bernero | | 513 | 455 | 58 |
| 2003-07-03 | @ BAL | 86 | L 5-6 | 47-39 | 3 | 27,022 | Doug Davis | Jason Johnson | Jason Johnson | Doug Davis | Jorge Julio | 518 | 461 | 57 |
| 2003-07-04 | @ BAL | 87 | L 5-8 | 47-40 | 3 | 25,641 | Kelvim Escobar | Rick Helling | Travis Driskill | Aquilino Lopez | Jorge Julio | 523 | 469 | 54 |
| 2003-07-05 | @ BAL | 88 | L 2-9 | 47-41 | 3 | 29,859 | Cory Lidle | Sidney Ponson | Sidney Ponson | Cory Lidle | | 525 | 478 | 47 |
| 2003-07-06 | @ BAL | 89 | W 5-3 | 48-41 | 3 | 30,284 | Mark Hendrickson | Rodrigo Lopez | Juan Acevedo | Kerry Ligtenberg | | 530 | 481 | 49 |
| 2003-07-08 | vs BOS | 90 | L 1-2 | 48-42 | 3 | 20,022 | Roy Halladay | Tim Wakefield | Todd Jones | Jeff Tam | Byung-Hyun Kim | 531 | 483 | 48 |
| 2003-07-09 | vs BOS | 91 | L 7-8 | 48-43 | 3 | 23,551 | Kelvim Escobar | Derek Lowe | Brandon Lyon | Jeff Tam | Byung-Hyun Kim | 538 | 491 | 47 |
| 2003-07-10 | vs BOS | 92 | L 1-7 | 48-44 | 3 | 20,113 | Cory Lidle | Ramiro Mendoza | Ramiro Mendoza | Cory Lidle | | 539 | 498 | 41 |
| 2003-07-11 | vs NYA | 93 | L 5-8 | 48-45 | 3 | 27,652 | John Wasdin | Andy Pettitte | Andy Pettitte | Trever Miller | Mariano Rivera | 544 | 506 | 38 |
| 2003-07-12 | vs NYA | 94 | W 10-3 | 49-45 | 3 | 37,119 | Roy Halladay | Mike Mussina | Roy Halladay | Mike Mussina | | 554 | 509 | 45 |
| 2003-07-13 | vs NYA | 95 | L 2-6 | 49-46 | 3 | 32,664 | Kelvim Escobar | Jeff Weaver | Jeff Weaver | Kelvim Escobar | | 556 | 515 | 41 |
| 2003-07-17 | @ BOS | 96 | W 5-2 | 50-46 | 3 | 34,521 | Roy Halladay | Derek Lowe | Roy Halladay | Derek Lowe | | 561 | 517 | 44 |
| 2003-07-18 | @ BOS | 97 | W 4-1 | 51-46 | 3 | 34,136 | Kelvim Escobar | Tim Wakefield | Kelvim Escobar | Tim Wakefield | Trever Miller | 565 | 518 | 47 |
| 2003-07-19 | @ BOS | 98 | L 4-5 | 51-47 | 3 | 34,812 | Cory Lidle | Ramiro Mendoza | Byung-Hyun Kim | Aquilino Lopez | | 569 | 523 | 46 |
| 2003-07-20 | @ BOS | 99 | L 4-9 | 51-48 | 3 | 34,321 | John Wasdin | Pedro Martinez | Pedro Martinez | John Wasdin | | 573 | 532 | 41 |
| 2003-07-21 | @ NYA | 100 | W 8-0 | 52-48 | 3 | 51,958 | Mark Hendrickson | Jeff Weaver | Mark Hendrickson | Jeff Weaver | | 581 | 532 | 49 |
| 2003-07-23 | vs CHA | 101 | L 6-7 | 52-49 | 3 | 20,320 | Roy Halladay | Mark Buehrle | Rick White | Juan Acevedo | Damaso Marte | 587 | 539 | 48 |
| 2003-07-24 | vs CHA | 102 | L 3-4 | 52-50 | 3 | 18,438 | Kelvim Escobar | Jon Garland | Tom Gordon | Tanyon Sturtze | Rick White | 590 | 543 | 47 |
| 2003-07-25 | vs BAL | 103 | W 5-3 | 53-50 | 3 | 17,095 | Cory Lidle | Jason Johnson | Cory Lidle | Jason Johnson | Trever Miller | 595 | 546 | 49 |
| 2003-07-26 | vs BAL | 104 | L 2-7 | 53-51 | 3 | 23,168 | Mark Hendrickson | Pat Hentgen | Pat Hentgen | Mark Hendrickson | | 597 | 553 | 44 |
| 2003-07-27 | vs BAL | 105 | W 10-1 | 54-51 | 3 | 21,787 | Roy Halladay | Rodrigo Lopez | Roy Halladay | Rodrigo Lopez | | 607 | 554 | 53 |
| 2003-07-29 | vs TBA | 106 | L 8-9 | 54-52 | 3 | 21,007 | Kelvim Escobar | Geremi Gonzalez | Al Levine | Trever Miller | Lance Carter | 615 | 563 | 52 |
| 2003-07-30 | vs TBA | 107 | L 3-5 | 54-53 | 3 | 21,068 | Cory Lidle | Victor Zambrano | Victor Zambrano | Cory Lidle | Jesus Colome | 618 | 568 | 50 |
| 2003-07-31 | vs TBA | 108 | L 6-7 | 54-54 | 3 | 29,544 | Mark Hendrickson | Jorge Sosa | Jorge Sosa | Mark Hendrickson | Lance Carter | 624 | 575 | 49 |
| 2003-08-01 | @ ANA | 109 | L 0-5 | 54-55 | 3 | 42,635 | Roy Halladay | Ramon Ortiz | Ramon Ortiz | Roy Halladay | | 624 | 580 | 44 |
| 2003-08-02 | @ ANA | 110 | W 6-1 | 55-55 | 3 | 43,087 | Corey Thurman | Jarrod Washburn | Corey Thurman | Jarrod Washburn | | 630 | 581 | 49 |
| 2003-08-03 | @ ANA | 111 | W 4-0 | 56-55 | 3 | 42,198 | Kelvim Escobar | Scot Shields | Kelvim Escobar | Scot Shields | Cliff Politte | 634 | 581 | 53 |
| 2003-08-04 | @ TBA | 112 | L 1-10 | 56-56 | 3 | 8,193 | Cory Lidle | Victor Zambrano | Victor Zambrano | Cory Lidle | | 635 | 591 | 44 |
| 2003-08-05 | @ TBA | 113 | L 4-5 | 56-57 | 3 | 9,566 | Mark Hendrickson | Jorge Sosa | Jesus Colome | Juan Acevedo | | 639 | 596 | 43 |
| 2003-08-06 | @ TBA | 114 | W 7-3 | 57-57 | 3 | 9,430 | Roy Halladay | Joe Kennedy | Roy Halladay | Joe Kennedy | | 646 | 599 | 47 |
| 2003-08-08 | vs TEX | 115 | L 3-5 | 57-58 | 3 | 24,392 | Corey Thurman | R.A. Dickey | R.A. Dickey | Corey Thurman | Francisco Cordero | 649 | 604 | 45 |
| 2003-08-09 | vs TEX | 116 | W 5-3 | 58-58 | 3 | 24,644 | Kelvim Escobar | Robert Ellis | Kelvim Escobar | Aaron Fultz | Aquilino Lopez | 654 | 607 | 47 |
| 2003-08-10 | vs TEX | 117 | L 4-5 | 58-59 | 3 | 25,401 | Josh Towers | Colby Lewis | Colby Lewis | Josh Towers | Francisco Cordero | 658 | 612 | 46 |
| 2003-08-11 | @ SEA | 118 | W 5-3 | 59-59 | 3 | 44,922 | Mark Hendrickson | Joel Pineiro | Mark Hendrickson | Joel Pineiro | Aquilino Lopez | 663 | 615 | 48 |
| 2003-08-12 | @ SEA | 119 | L 1-3 | 59-60 | 3 | 37,018 | Roy Halladay | Freddy Garcia | Freddy Garcia | Roy Halladay | Shigetoshi Hasegawa | 664 | 618 | 46 |
| 2003-08-13 | @ SEA | 120 | L 6-13 | 59-61 | 3 | 37,066 | Corey Thurman | Ryan Franklin | Julio Mateo | Jason Kershner | | 670 | 631 | 39 |
| 2003-08-14 | @ SEA | 121 | W 5-2 | 60-61 | 3 | 41,945 | Kelvim Escobar | Gil Meche | Kelvim Escobar | Gil Meche | Aquilino Lopez | 675 | 633 | 42 |
| 2003-08-15 | @ OAK | 122 | W 8-5 | 61-61 | 3 | 17,446 | Josh Towers | Rich Harden | Josh Towers | Rich Harden | Trever Miller | 683 | 638 | 45 |
| 2003-08-16 | @ OAK | 123 | L 4-6 | 61-62 | 3 | 31,045 | Mark Hendrickson | Tim Hudson | Tim Hudson | Mark Hendrickson | Keith Foulke | 687 | 644 | 43 |
| 2003-08-17 | @ OAK | 124 | L 3-7 | 61-63 | 3 | 32,488 | Roy Halladay | Barry Zito | Barry Zito | Roy Halladay | Keith Foulke | 690 | 651 | 39 |
| 2003-08-19 | vs SEA | 125 | L 1-9 | 61-64 | 3 | 24,025 | Kelvim Escobar | Ryan Franklin | Ryan Franklin | Kelvim Escobar | | 691 | 660 | 31 |
| 2003-08-20 | vs SEA | 126 | W 5-2 | 62-64 | 3 | 21,588 | Josh Towers | Gil Meche | Josh Towers | Gil Meche | | 696 | 662 | 34 |
| 2003-08-21 | vs SEA | 127 | W 7-3 | 63-64 | 3 | 20,111 | Mark Hendrickson | Jamie Moyer | Mark Hendrickson | Jamie Moyer | | 703 | 665 | 38 |
| 2003-08-22 | vs OAK | 128 | W 6-3 | 64-64 | 3 | 22,050 | Roy Halladay | Barry Zito | Roy Halladay | Barry Zito | Aquilino Lopez | 709 | 668 | 41 |
| 2003-08-23 | vs OAK | 129 | L 5-11 | 64-65 | 3 | 27,740 | Pete Walker | John Halama | Mike Wood | Tanyon Sturtze | | 714 | 679 | 35 |
| 2003-08-24 | vs OAK | 130 | L 2-17 | 64-66 | 3 | 32,979 | Kelvim Escobar | Tim Hudson | Tim Hudson | Kelvim Escobar | Michael Neu | 716 | 696 | 20 |
| 2003-08-25 | vs OAK | 131 | L 6-8 | 64-67 | 3 | 22,111 | Cory Lidle | Ted Lilly | Ted Lilly | Cory Lidle | Keith Foulke | 722 | 704 | 18 |
| 2003-08-26 | @ BOS | 132 | W 12-9 | 65-67 | 3 | 33,731 | Mark Hendrickson | Tim Wakefield | Josh Towers | Scott Sauerbeck | Aquilino Lopez | 734 | 713 | 21 |
| 2003-08-27 | @ BOS | 133 | L 3-6 | 65-68 | 3 | 34,206 | Roy Halladay | John Burkett | Mike Timlin | Roy Halladay | Byung-Hyun Kim | 737 | 719 | 18 |
| 2003-08-29 | @ CLE | 134 | W 7-3 | 66-68 | 3 | 21,008 | Kelvim Escobar | CC Sabathia | Kelvim Escobar | CC Sabathia | | 744 | 722 | 22 |
| 2003-08-30 | @ CLE | 135 | W 9-3 | 67-68 | 3 | 21,806 | Cory Lidle | Jake Westbrook | Cory Lidle | Jake Westbrook | Josh Towers | 753 | 725 | 28 |
| 2003-08-31 | @ CLE | 136 | L 4-5 | 67-69 | 3 | 20,866 | Mark Hendrickson | Billy Traber | Danys Baez | Jason Kershner | | 757 | 730 | 27 |
| 2003-09-01 | vs NYA | 137 | W 8-1 | 68-69 | 3 | 26,869 | Roy Halladay | David Wells | Roy Halladay | David Wells | | 765 | 731 | 34 |
| 2003-09-03 | vs NYA | 138 | W 4-3 | 69-69 | 3 | 21,770 | Kelvim Escobar | Mike Mussina | Jason Kershner | Antonio Osuna | Aquilino Lopez | 769 | 734 | 35 |
| 2003-09-04 | vs NYA | 139 | L 2-3 | 69-70 | 3 | 17,254 | Cory Lidle | Jose Contreras | Jose Contreras | Pete Walker | Mariano Rivera | 771 | 737 | 34 |
| 2003-09-05 | vs DET | 140 | W 8-6 | 70-70 | 3 | 14,455 | Mark Hendrickson | Mike Maroth | Tanyon Sturtze | Mike Maroth | Aquilino Lopez | 779 | 743 | 36 |
| 2003-09-06 | vs DET | 141 | W 1-0 | 71-70 | 3 | 18,261 | Roy Halladay | Nate Cornejo | Roy Halladay | Fernando Rodney | | 780 | 743 | 37 |
| 2003-09-07 | vs DET | 142 | W 8-0 | 72-70 | 3 | 16,617 | Josh Towers | Chris Mears | Josh Towers | Chris Mears | | 788 | 743 | 45 |
| 2003-09-08 | @ NYA | 143 | L 3-9 | 72-71 | 3 | 8,848 | Kelvim Escobar | Mike Mussina | Mike Mussina | Kelvim Escobar | | 791 | 752 | 39 |
| 2003-09-09 | @ TBA | 144 | L 6-11 | 72-72 | 3 | 8,528 | Cory Lidle | Doug Waechter | Doug Waechter | Cory Lidle | Joe Kennedy | 797 | 763 | 34 |
| 2003-09-10 | @ TBA | 145 | W 6-5 | 73-72 | 3 | 8,522 | Mark Hendrickson | Jorge Sosa | Mark Hendrickson | Jorge Sosa | Aquilino Lopez | 803 | 768 | 35 |
| 2003-09-11 | @ TBA | 146 | W 3-1 | 74-72 | 3 | 9,345 | Roy Halladay | Geremi Gonzalez | Roy Halladay | Geremi Gonzalez | | 806 | 769 | 37 |
| 2003-09-12 | vs BAL | 147 | W 4-2 | 75-72 | 3 | 15,274 | Josh Towers | Eric DuBose | Josh Towers | Eric DuBose | Aquilino Lopez | 810 | 771 | 39 |
| 2003-09-13 | vs BAL | 148 | W 6-1 | 76-72 | 3 | 18,309 | Kelvim Escobar | Pat Hentgen | Kelvim Escobar | Pat Hentgen | | 816 | 772 | 44 |
| 2003-09-14 | vs BAL | 149 | L 3-5 | 76-73 | 3 | 18,763 | Cory Lidle | Matt Riley | Matt Riley | Cory Lidle | Jorge Julio | 819 | 777 | 42 |
| 2003-09-16 | @ DET | 150 | W 9-6 | 77-73 | 3 | 9,801 | Pete Walker | Nate Cornejo | Jason Kershner | Nate Cornejo | | 828 | 783 | 45 |
| 2003-09-17 | @ DET | 151 | W 6-0 | 78-73 | 3 | 11,240 | Roy Halladay | Shane Loux | Roy Halladay | Shane Loux | | 834 | 783 | 51 |
| 2003-09-18 | @ DET | 152 | W 10-6 | 79-73 | 3 | 9,951 | Josh Towers | Mike Maroth | Josh Towers | Mike Maroth | | 844 | 789 | 55 |
| 2003-09-19 | @ BAL | 153 | W 5-2 | 80-73 | 3 | 25,857 | Kelvim Escobar | Omar Daal | Kelvim Escobar | Hector Carrasco | Aquilino Lopez | 849 | 791 | 58 |
| 2003-09-20 | @ BAL | 154 | L 1-2 | 80-74 | 3 | 32,381 | Cory Lidle | Matt Riley | Kerry Ligtenberg | Cory Lidle | Jorge Julio | 850 | 793 | 57 |
| 2003-09-21 | @ BAL | 155 | W 7-4 | 81-74 | 3 | 27,502 | Mark Hendrickson | Rodrigo Lopez | Pete Walker | Hector Carrasco | Aquilino Lopez | 857 | 797 | 60 |
| 2003-09-22 | vs TBA | 156 | L 2-5 | 81-75 | 3 | 22,869 | Roy Halladay | Rob Bell | Rob Bell | Roy Halladay | | 859 | 802 | 57 |
| 2003-09-23 | vs TBA | 157 | W 8-5 | 82-75 | 3 | 17,208 | Josh Towers | Victor Zambrano | Jason Kershner | Victor Zambrano | | 867 | 807 | 60 |
| 2003-09-24 | vs TBA | 158 | W 5-3 | 83-75 | 3 | 16,050 | Kelvim Escobar | Doug Waechter | Kelvim Escobar | Doug Waechter | Aquilino Lopez | 872 | 810 | 62 |
| 2003-09-25 | vs TBA | 159 | W 10-8 | 84-75 | 3 | 13,408 | Pete Walker | Jorge Sosa | Trever Miller | Lance Carter | | 882 | 818 | 64 |
| 2003-09-26 | vs CLE | 160 | L 1-2 | 84-76 | 3 | 13,861 | Cory Lidle | Jason Stanford | Jason Stanford | Cory Lidle | David Riske | 883 | 820 | 63 |
| 2003-09-27 | vs CLE | 161 | W 5-4 | 85-76 | 3 | 21,504 | Roy Halladay | Terry Mulholland | Roy Halladay | Terry Mulholland | | 888 | 824 | 64 |
| 2003-09-28 | vs CLE | 162 | W 6-2 | 86-76 | 3 | 22,014 | Josh Towers | Cliff Lee | Josh Towers | Cliff Lee | | 894 | 826 | 68 |