| 2003-03-31 | vs CHN | 1 | L 2-15 | 0-1 | 5 | 53,586 | Tom Glavine | Kerry Wood | Kerry Wood | Tom Glavine | | 2 | 15 | -13 |
| 2003-04-02 | vs CHN | 2 | W 4-1 | 1-1 | 3 | 20,594 | Al Leiter | Matt Clement | Al Leiter | Matt Clement | Armando Benitez | 6 | 16 | -10 |
| 2003-04-03 | vs CHN | 3 | L 3-6 | 1-2 | 4 | 17,244 | Steve Trachsel | Mark Prior | Mark Prior | Steve Trachsel | | 9 | 22 | -13 |
| 2003-04-04 | vs MON | 4 | W 4-0 | 2-2 | 2 | 18,040 | David Cone | Tomo Ohka | David Cone | Tomo Ohka | | 13 | 22 | -9 |
| 2003-04-05 | vs MON | 5 | W 3-1 | 3-2 | 2 | 36,817 | Tom Glavine | Tony Armas | Tom Glavine | Tony Armas | Armando Benitez | 16 | 23 | -7 |
| 2003-04-06 | vs MON | 6 | L 5-8 | 3-3 | 2 | 35,093 | Jae Weong Seo | Livan Hernandez | Scott Stewart | Armando Benitez | Rocky Biddle | 21 | 31 | -10 |
| 2003-04-08 | @ FLO | 7 | W 4-2 | 4-3 | 2 | 10,103 | Al Leiter | Mark Redman | Al Leiter | Mark Redman | Armando Benitez | 25 | 33 | -8 |
| 2003-04-09 | @ FLO | 8 | L 2-3 | 4-4 | 3 | 10,052 | Steve Trachsel | A.J. Burnett | Braden Looper | Mike Stanton | | 27 | 36 | -9 |
| 2003-04-10 | @ FLO | 9 | L 3-4 | 4-5 | 3 | 10,267 | Tom Glavine | Josh Beckett | Tim Spooneybarger | Armando Benitez | | 30 | 40 | -10 |
| 2003-04-11 | @ MON | 10 | L 0-10 | 4-6 | 4 | 17,906 | David Cone | Tomo Ohka | Tomo Ohka | David Cone | | 30 | 50 | -20 |
| 2003-04-12 | @ MON | 11 | L 4-5 | 4-7 | 4 | 18,264 | Jae Weong Seo | Livan Hernandez | Livan Hernandez | Jae Weong Seo | Rocky Biddle | 34 | 55 | -21 |
| 2003-04-13 | @ MON | 12 | L 1-2 | 4-8 | 5 | 16,332 | Al Leiter | Zach Day | Rocky Biddle | Mike Stanton | | 35 | 57 | -22 |
| 2003-04-14 | @ MON | 13 | L 3-5 | 4-9 | 5 | 13,155 | Steve Trachsel | Javier Vazquez | Dan Smith | Scott Strickland | Rocky Biddle | 38 | 62 | -24 |
| 2003-04-15 | @ PIT | 14 | W 3-1 | 5-9 | 5 | 14,728 | Tom Glavine | Josh Fogg | Tom Glavine | Josh Fogg | Armando Benitez | 41 | 63 | -22 |
| 2003-04-16 | @ PIT | 15 | L 3-6 | 5-10 | 5 | 12,609 | David Cone | Jeff Suppan | Jeff Suppan | David Cone | | 44 | 69 | -25 |
| 2003-04-17 | @ PIT | 16 | W 7-2 | 6-10 | 5 | 11,299 | Jae Weong Seo | Jeff D'Amico | Jae Weong Seo | Jeff D'Amico | | 51 | 71 | -20 |
| 2003-04-18 | vs FLO | 17 | W 6-3 | 7-10 | 5 | 18,525 | Al Leiter | Mark Redman | David Weathers | Vladimir Nunez | Armando Benitez | 57 | 74 | -17 |
| 2003-04-19 | vs FLO | 18 | L 5-6 | 7-11 | 5 | 36,448 | Steve Trachsel | A.J. Burnett | Braden Looper | Armando Benitez | | 62 | 80 | -18 |
| 2003-04-20 | vs FLO | 19 | W 7-4 | 8-11 | 5 | 26,245 | Tom Glavine | Josh Beckett | Tom Glavine | Vladimir Nunez | | 69 | 84 | -15 |
| 2003-04-22 | vs HOU | 20 | L 2-6 | 8-12 | 5 | 31,733 | David Cone | Tim Redding | Tim Redding | David Cone | | 71 | 90 | -19 |
| 2003-04-23 | vs HOU | 21 | W 4-2 | 9-12 | 5 | 20,322 | Al Leiter | Roy Oswalt | Al Leiter | Roy Oswalt | Armando Benitez | 75 | 92 | -17 |
| 2003-04-24 | vs HOU | 22 | W 7-4 | 10-12 | 5 | 31,656 | Pedro Astacio | Wade Miller | Pedro Astacio | Wade Miller | Armando Benitez | 82 | 96 | -14 |
| 2003-04-25 | vs ARI | 23 | W 4-3 | 11-12 | 5 | 24,725 | Steve Trachsel | Miguel Batista | Mike Stanton | Oscar Villarreal | Armando Benitez | 86 | 99 | -13 |
| 2003-04-27 | vs ARI | 24 | L 1-6 | 11-14 | 5 | 36,491 | Tom Glavine | Brandon Webb | Brandon Webb | Tom Glavine | | 87 | 105 | -18 |
| 2003-04-27 | vs ARI | 25 | L 3-7 | 11-14 | 5 | 36,491 | Jae Weong Seo | Randy Johnson | Randy Johnson | Jae Weong Seo | Matt Mantei | 90 | 112 | -22 |
| 2003-04-29 | @ SLN | 26 | L 3-13 | 11-15 | 5 | 30,275 | Al Leiter | Matt Morris | Matt Morris | Al Leiter | | 93 | 125 | -32 |
| 2003-04-30 | @ SLN | 27 | L 4-13 | 11-16 | 5 | 30,265 | Pedro Astacio | Woody Williams | Woody Williams | Pedro Astacio | | 97 | 138 | -41 |
| 2003-05-01 | @ SLN | 28 | L 5-6 | 11-17 | 5 | 35,283 | Steve Trachsel | Brett Tomko | Cal Eldred | Scott Strickland | | 102 | 144 | -42 |
| 2003-05-02 | @ MIL | 29 | W 9-3 | 12-17 | 5 | 16,315 | Tom Glavine | Glendon Rusch | Tom Glavine | Glendon Rusch | | 111 | 147 | -36 |
| 2003-05-03 | @ MIL | 30 | L 2-3 | 12-18 | 5 | 19,796 | Jae Weong Seo | Ruben Quevedo | John Foster | David Weathers | Mike DeJean | 113 | 150 | -37 |
| 2003-05-04 | @ MIL | 31 | W 5-3 | 13-18 | 5 | 18,571 | Al Leiter | Matt Kinney | Al Leiter | Matt Kinney | Armando Benitez | 118 | 153 | -35 |
| 2003-05-06 | vs LAN | 32 | W 3-2 | 14-18 | 5 | 21,173 | Pedro Astacio | Odalis Perez | Pedro Astacio | Odalis Perez | Armando Benitez | 121 | 155 | -34 |
| 2003-05-07 | vs LAN | 33 | L 1-2 | 14-19 | 5 | 18,965 | Steve Trachsel | Hideo Nomo | Hideo Nomo | Steve Trachsel | Eric Gagne | 122 | 157 | -35 |
| 2003-05-08 | vs LAN | 34 | L 1-6 | 14-20 | 5 | 18,729 | Tom Glavine | Kazuhisa Ishii | Kazuhisa Ishii | Tom Glavine | | 123 | 163 | -40 |
| 2003-05-09 | vs SDN | 35 | L 4-5 | 14-21 | 5 | 29,855 | Jae Weong Seo | Mike Bynum | Luther Hackman | David Weathers | Jesse Orosco | 127 | 168 | -41 |
| 2003-05-10 | vs SDN | 36 | W 4-2 | 15-21 | 5 | 32,930 | Al Leiter | Roger Deago | Mike Stanton | Jaret Wright | | 131 | 170 | -39 |
| 2003-05-11 | vs SDN | 37 | W 3-2 | 16-21 | 5 | 30,694 | Pedro Astacio | Jake Peavy | Graeme Lloyd | Mike Matthews | Armando Benitez | 134 | 172 | -38 |
| 2003-05-12 | @ COL | 38 | W 9-6 | 17-21 | 5 | 25,433 | Steve Trachsel | Jason Young | Steve Trachsel | Jason Young | Armando Benitez | 143 | 178 | -35 |
| 2003-05-13 | @ COL | 39 | L 8-9 | 17-22 | 5 | 25,043 | Tom Glavine | Shawn Chacon | Steve Reed | Jaime Cerda | Jose Jimenez | 151 | 187 | -36 |
| 2003-05-14 | @ COL | 40 | L 5-6 | 17-23 | 5 | 26,755 | Jae Weong Seo | Darren Oliver | Steve Reed | Mike Stanton | Jose Jimenez | 156 | 193 | -37 |
| 2003-05-15 | @ SFN | 41 | L 3-11 | 17-24 | 5 | 36,542 | Al Leiter | Kirk Rueter | Kirk Rueter | Al Leiter | | 159 | 204 | -45 |
| 2003-05-16 | @ SFN | 42 | L 5-7 | 17-25 | 5 | 39,160 | Pedro Astacio | Jason Schmidt | Joe Nathan | David Weathers | Tim Worrell | 164 | 211 | -47 |
| 2003-05-17 | @ SFN | 43 | W 5-1 | 18-25 | 5 | 42,259 | Steve Trachsel | Damian Moss | Steve Trachsel | Damian Moss | | 169 | 212 | -43 |
| 2003-05-18 | @ SFN | 44 | W 5-1 | 19-25 | 4 | 42,590 | Tom Glavine | Kurt Ainsworth | Tom Glavine | Kurt Ainsworth | | 174 | 213 | -39 |
| 2003-05-20 | vs PHI | 45 | L 7-11 | 19-26 | 4 | 25,281 | Jae Weong Seo | Brett Myers | Brett Myers | Graeme Lloyd | | 181 | 224 | -43 |
| 2003-05-21 | vs PHI | 46 | W 5-4 | 20-26 | 4 | 29,551 | Al Leiter | Randy Wolf | Armando Benitez | Terry Adams | | 186 | 228 | -42 |
| 2003-05-22 | vs PHI | 47 | W 6-3 | 21-26 | 4 | 20,101 | Pedro Astacio | Vicente Padilla | Pedro Astacio | Vicente Padilla | Armando Benitez | 192 | 231 | -39 |
| 2003-05-23 | @ ATL | 48 | W 6-5 | 22-26 | 4 | 33,270 | Steve Trachsel | Russ Ortiz | Steve Trachsel | Russ Ortiz | Armando Benitez | 198 | 236 | -38 |
| 2003-05-24 | @ ATL | 49 | L 4-10 | 22-27 | 4 | 40,912 | Tom Glavine | Horacio Ramirez | Horacio Ramirez | Tom Glavine | | 202 | 246 | -44 |
| 2003-05-25 | @ ATL | 50 | L 1-3 | 22-28 | 4 | 41,432 | Jae Weong Seo | Greg Maddux | Roberto Hernandez | David Weathers | John Smoltz | 203 | 249 | -46 |
| 2003-05-27 | @ PHI | 51 | W 4-2 | 23-28 | 4 | 18,081 | Al Leiter | Randy Wolf | Al Leiter | Randy Wolf | Armando Benitez | 207 | 251 | -44 |
| 2003-05-28 | @ PHI | 52 | L 3-11 | 23-29 | 5 | 21,389 | Pedro Astacio | Vicente Padilla | Vicente Padilla | Pedro Astacio | | 210 | 262 | -52 |
| 2003-05-29 | @ PHI | 53 | W 5-0 | 24-29 | 5 | 19,568 | Steve Trachsel | Kevin Millwood | Steve Trachsel | Kevin Millwood | | 215 | 262 | -47 |
| 2003-05-30 | vs ATL | 54 | L 2-5 | 24-30 | 5 | 26,439 | Tom Glavine | Greg Maddux | Greg Maddux | Tom Glavine | John Smoltz | 217 | 267 | -50 |
| 2003-05-31 | vs ATL | 55 | W 4-2 | 25-30 | 5 | 33,378 | Jae Weong Seo | Mike Hampton | Jae Weong Seo | Mike Hampton | Armando Benitez | 221 | 269 | -48 |
| 2003-06-01 | vs ATL | 56 | W 10-4 | 26-30 | 4 | 25,162 | Al Leiter | Horacio Ramirez | Al Leiter | Kevin Gryboski | | 231 | 273 | -42 |
| 2003-06-05 | vs MIL | 57 | L 7-8 | 26-32 | 5 | 0 | Steve Trachsel | Matt Kinney | Matt Kinney | Steve Trachsel | Mike DeJean | 238 | 281 | -43 |
| 2003-06-05 | vs MIL | 58 | L 3-5 | 26-32 | 5 | 19,048 | Tom Glavine | Ben Sheets | Ben Sheets | Tom Glavine | Mike DeJean | 241 | 286 | -45 |
| 2003-06-06 | vs SEA | 59 | W 3-2 | 27-32 | 5 | 26,684 | Jae Weong Seo | Ryan Franklin | Jae Weong Seo | Ryan Franklin | Armando Benitez | 244 | 288 | -44 |
| 2003-06-08 | vs SEA | 60 | L 1-13 | 27-34 | 5 | 0 | Al Leiter | Freddy Garcia | Freddy Garcia | Al Leiter | | 245 | 301 | -56 |
| 2003-06-08 | vs SEA | 61 | L 0-7 | 27-34 | 5 | 39,820 | Michael Bacsik | Jamie Moyer | Jamie Moyer | Michael Bacsik | | 245 | 308 | -63 |
| 2003-06-10 | @ TEX | 62 | L 7-9 | 27-35 | 5 | 20,581 | Steve Trachsel | John Thomson | John Thomson | Steve Trachsel | Ugueth Urbina | 252 | 317 | -65 |
| 2003-06-11 | @ TEX | 63 | W 8-2 | 28-35 | 5 | 19,087 | Jae Weong Seo | Victor Santos | Jae Weong Seo | Victor Santos | | 260 | 319 | -59 |
| 2003-06-12 | @ TEX | 64 | W 11-0 | 29-35 | 5 | 19,044 | Al Leiter | Colby Lewis | Al Leiter | Colby Lewis | | 271 | 319 | -48 |
| 2003-06-13 | @ ANA | 65 | W 7-3 | 30-35 | 5 | 38,294 | Michael Bacsik | Aaron Sele | Michael Bacsik | Aaron Sele | | 278 | 322 | -44 |
| 2003-06-14 | @ ANA | 66 | L 3-13 | 30-36 | 5 | 43,449 | Jason Roach | Ramon Ortiz | Ramon Ortiz | Jason Roach | | 281 | 335 | -54 |
| 2003-06-15 | @ ANA | 67 | W 8-0 | 31-36 | 5 | 43,721 | Steve Trachsel | Jarrod Washburn | Steve Trachsel | Jarrod Washburn | | 289 | 335 | -46 |
| 2003-06-16 | @ FLO | 68 | L 0-1 | 31-37 | 5 | 10,624 | Tom Glavine | Dontrelle Willis | Dontrelle Willis | Tom Glavine | | 289 | 336 | -47 |
| 2003-06-17 | @ FLO | 69 | W 5-0 | 32-37 | 5 | 10,359 | Jae Weong Seo | Carl Pavano | Jae Weong Seo | Carl Pavano | | 294 | 336 | -42 |
| 2003-06-18 | @ FLO | 70 | W 10-5 | 33-37 | 4 | 11,326 | Al Leiter | Brad Penny | Al Leiter | Brad Penny | Dan Wheeler | 304 | 341 | -37 |
| 2003-06-19 | @ FLO | 71 | L 1-5 | 33-38 | 5 | 10,400 | Michael Bacsik | Tommy Phelps | Tommy Phelps | Michael Bacsik | | 305 | 346 | -41 |
| 2003-06-20 | vs NYA | 72 | L 0-5 | 33-39 | 5 | 55,386 | Steve Trachsel | Andy Pettitte | Andy Pettitte | Steve Trachsel | | 305 | 351 | -46 |
| 2003-06-22 | vs NYA | 73 | L 3-7 | 33-40 | 5 | 55,031 | Tom Glavine | David Wells | Mariano Rivera | Graeme Lloyd | | 308 | 358 | -50 |
| 2003-06-24 | vs FLO | 74 | L 4-8 | 33-41 | 5 | 22,226 | Al Leiter | Brad Penny | Brad Penny | Al Leiter | Michael Tejera | 312 | 366 | -54 |
| 2003-06-25 | vs FLO | 75 | W 6-3 | 34-41 | 5 | 22,563 | Steve Trachsel | Mark Redman | Steve Trachsel | Mark Redman | Armando Benitez | 318 | 369 | -51 |
| 2003-06-26 | vs FLO | 76 | L 1-6 | 34-42 | 5 | 30,378 | Aaron Heilman | Dontrelle Willis | Dontrelle Willis | Aaron Heilman | | 319 | 375 | -56 |
| 2003-06-27 | @ NYA | 77 | L 4-6 | 34-43 | 5 | 55,226 | Jae Weong Seo | David Wells | David Wells | Jae Weong Seo | Dan Miceli | 323 | 381 | -58 |
| 2003-06-28 | @ NYA | 78 | L 1-7 | 34-44 | 5 | 55,343 | Jeremy Griffiths | Roger Clemens | Roger Clemens | Jeremy Griffiths | | 324 | 388 | -64 |
| 2003-06-28 | vs NYA | 79 | L 8-9 | 34-44 | 5 | 36,372 | Tom Glavine | Brandon Claussen | Brandon Claussen | Tom Glavine | Mariano Rivera | 332 | 397 | -65 |
| 2003-06-29 | @ NYA | 80 | L 3-5 | 34-45 | 5 | 55,444 | Al Leiter | Jeff Weaver | Jeff Weaver | Al Leiter | Mariano Rivera | 335 | 402 | -67 |
| 2003-06-30 | vs MON | 81 | W 3-1 | 35-45 | 5 | 29,829 | Steve Trachsel | Javier Vazquez | Steve Trachsel | Javier Vazquez | Armando Benitez | 338 | 403 | -65 |
| 2003-07-01 | vs MON | 82 | W 7-6 | 36-45 | 5 | 30,084 | Aaron Heilman | Sun-Woo Kim | Armando Benitez | Julio Manon | | 345 | 409 | -64 |
| 2003-07-02 | vs MON | 83 | L 4-11 | 36-46 | 5 | 35,547 | Jae Weong Seo | Livan Hernandez | Livan Hernandez | Jae Weong Seo | | 349 | 420 | -71 |
| 2003-07-04 | @ CIN | 84 | W 7-2 | 37-46 | 5 | 35,111 | Tom Glavine | Jimmy Haynes | Tom Glavine | Jimmy Haynes | Armando Benitez | 356 | 422 | -66 |
| 2003-07-05 | @ CIN | 85 | W 6-2 | 38-46 | 5 | 41,020 | Steve Trachsel | Danny Graves | Steve Trachsel | Danny Graves | David Weathers | 362 | 424 | -62 |
| 2003-07-06 | @ CIN | 86 | W 7-5 | 39-46 | 5 | 31,054 | Aaron Heilman | Paul Wilson | Jaime Cerda | Brian Reith | Armando Benitez | 369 | 429 | -60 |
| 2003-07-07 | vs ATL | 87 | L 3-7 | 39-47 | 5 | 32,399 | Jae Weong Seo | Horacio Ramirez | Horacio Ramirez | Jae Weong Seo | | 372 | 436 | -64 |
| 2003-07-08 | vs ATL | 88 | L 3-5 | 39-48 | 5 | 29,096 | Jason Roach | Shane Reynolds | Shane Reynolds | Jason Roach | John Smoltz | 375 | 441 | -66 |
| 2003-07-09 | vs ATL | 89 | L 3-6 | 39-49 | 5 | 30,308 | Tom Glavine | Russ Ortiz | Russ Ortiz | Tom Glavine | John Smoltz | 378 | 447 | -69 |
| 2003-07-10 | vs PHI | 90 | L 2-7 | 39-50 | 5 | 25,913 | Steve Trachsel | Vicente Padilla | Vicente Padilla | Steve Trachsel | | 380 | 454 | -74 |
| 2003-07-11 | vs PHI | 91 | L 3-10 | 39-51 | 5 | 35,884 | Aaron Heilman | Randy Wolf | Randy Wolf | Aaron Heilman | | 383 | 464 | -81 |
| 2003-07-12 | vs PHI | 92 | L 2-4 | 39-52 | 5 | 33,452 | Jae Weong Seo | Brandon Duckworth | Jose Mesa | John Franco | | 385 | 468 | -83 |
| 2003-07-13 | vs PHI | 93 | W 4-3 | 40-52 | 5 | 31,630 | Tom Glavine | Brett Myers | Armando Benitez | Terry Adams | | 389 | 471 | -82 |
| 2003-07-17 | @ ATL | 94 | L 2-3 | 40-53 | 5 | 36,688 | Steve Trachsel | Greg Maddux | Greg Maddux | John Franco | | 391 | 474 | -83 |
| 2003-07-18 | @ ATL | 95 | L 4-11 | 40-54 | 5 | 44,815 | Jae Weong Seo | Mike Hampton | Mike Hampton | Jae Weong Seo | | 395 | 485 | -90 |
| 2003-07-19 | @ ATL | 96 | L 4-7 | 40-55 | 5 | 45,759 | Tom Glavine | Russ Ortiz | Russ Ortiz | Tom Glavine | John Smoltz | 399 | 492 | -93 |
| 2003-07-20 | @ ATL | 97 | L 8-11 | 40-56 | 5 | 36,029 | Al Leiter | Horacio Ramirez | Ray King | Mike Stanton | John Smoltz | 407 | 503 | -96 |
| 2003-07-21 | @ PHI | 98 | W 8-6 | 41-56 | 5 | 33,208 | Aaron Heilman | Brandon Duckworth | Aaron Heilman | Brandon Duckworth | John Franco | 415 | 509 | -94 |
| 2003-07-22 | @ PHI | 99 | W 7-5 | 42-56 | 5 | 37,164 | Steve Trachsel | Kevin Millwood | Steve Trachsel | Kevin Millwood | Dan Wheeler | 422 | 514 | -92 |
| 2003-07-23 | @ MON | 100 | L 2-5 | 42-57 | 5 | 8,853 | Jae Weong Seo | Javier Vazquez | Javier Vazquez | Jae Weong Seo | Rocky Biddle | 424 | 519 | -95 |
| 2003-07-24 | @ MON | 101 | L 1-5 | 42-58 | 5 | 9,337 | Tom Glavine | Livan Hernandez | Livan Hernandez | Tom Glavine | Rocky Biddle | 425 | 524 | -99 |
| 2003-07-25 | vs CIN | 102 | W 3-1 | 43-58 | 5 | 34,021 | Al Leiter | Danny Graves | Al Leiter | Danny Graves | Mike Stanton | 428 | 525 | -97 |
| 2003-07-26 | vs CIN | 103 | L 3-8 | 43-59 | 5 | 29,305 | Aaron Heilman | Jose Acevedo | Jose Acevedo | Aaron Heilman | | 431 | 533 | -102 |
| 2003-07-27 | vs CIN | 104 | L 5-8 | 43-60 | 5 | 30,173 | Steve Trachsel | Paul Wilson | Paul Wilson | Steve Trachsel | Scott Williamson | 436 | 541 | -105 |
| 2003-07-28 | vs MIL | 105 | L 2-4 | 43-61 | 5 | 6,056 | Jae Weong Seo | Glendon Rusch | Leo Estrella | David Weathers | Danny Kolb | 438 | 545 | -107 |
| 2003-07-29 | vs MIL | 106 | L 3-6 | 43-62 | 5 | 22,846 | Tom Glavine | Ben Sheets | Ben Sheets | Dan Wheeler | Mike DeJean | 441 | 551 | -110 |
| 2003-07-30 | vs MIL | 107 | W 2-0 | 44-62 | 5 | 22,389 | Al Leiter | Wes Obermueller | Al Leiter | Wes Obermueller | David Weathers | 443 | 551 | -108 |
| 2003-07-31 | vs MIL | 108 | L 3-4 | 44-63 | 5 | 27,590 | Aaron Heilman | Matt Kinney | Matt Kinney | Aaron Heilman | Danny Kolb | 446 | 555 | -109 |
| 2003-08-01 | vs SLN | 109 | L 2-8 | 44-64 | 5 | 23,578 | Steve Trachsel | Jeff Fassero | Steve Kline | Dan Wheeler | | 448 | 563 | -115 |
| 2003-08-02 | vs SLN | 110 | L 9-10 | 44-65 | 5 | 30,898 | Jae Weong Seo | Brett Tomko | Brett Tomko | Jae Weong Seo | Esteban Yan | 457 | 573 | -116 |
| 2003-08-03 | vs SLN | 111 | W 13-5 | 45-65 | 5 | 27,592 | Jeremy Griffiths | Garrett Stephenson | Jeremy Griffiths | Garrett Stephenson | | 470 | 578 | -108 |
| 2003-08-05 | @ HOU | 112 | W 10-1 | 46-65 | 5 | 31,582 | Al Leiter | Ron Villone | Al Leiter | Ron Villone | | 480 | 579 | -99 |
| 2003-08-06 | @ HOU | 113 | L 1-11 | 46-66 | 5 | 30,154 | Aaron Heilman | Wade Miller | Wade Miller | Aaron Heilman | | 481 | 590 | -109 |
| 2003-08-07 | @ HOU | 114 | W 5-4 | 47-66 | 5 | 31,250 | Steve Trachsel | Tim Redding | Steve Trachsel | Brad Lidge | Mike Stanton | 486 | 594 | -108 |
| 2003-08-08 | @ ARI | 115 | W 3-1 | 48-66 | 5 | 36,335 | Tom Glavine | Brandon Webb | Tom Glavine | Brandon Webb | Mike Stanton | 489 | 595 | -106 |
| 2003-08-09 | @ ARI | 116 | L 1-2 | 48-67 | 5 | 41,934 | Jae Weong Seo | Elmer Dessens | Steve Randolph | John Franco | | 490 | 597 | -107 |
| 2003-08-10 | @ ARI | 117 | L 4-7 | 48-68 | 5 | 37,521 | Al Leiter | Randy Johnson | Randy Johnson | Al Leiter | Matt Mantei | 494 | 604 | -110 |
| 2003-08-12 | vs SFN | 118 | W 5-4 | 49-68 | 5 | 37,461 | Aaron Heilman | Sidney Ponson | Aaron Heilman | Sidney Ponson | David Weathers | 499 | 608 | -109 |
| 2003-08-13 | vs SFN | 119 | W 9-2 | 50-68 | 5 | 31,759 | Steve Trachsel | Jerome Williams | Steve Trachsel | Jerome Williams | | 508 | 610 | -102 |
| 2003-08-15 | vs COL | 120 | W 5-0 | 51-68 | 5 | 28,081 | Tom Glavine | Darren Oliver | Tom Glavine | Darren Oliver | | 513 | 610 | -97 |
| 2003-08-16 | vs COL | 121 | W 13-4 | 52-68 | 5 | 28,233 | Jae Weong Seo | Shawn Chacon | Jae Weong Seo | Shawn Chacon | | 526 | 614 | -88 |
| 2003-08-17 | vs COL | 122 | W 6-4 | 53-68 | 5 | 28,393 | Al Leiter | Jason Jennings | Al Leiter | Jason Jennings | David Weathers | 532 | 618 | -86 |
| 2003-08-18 | vs COL | 123 | W 8-0 | 54-68 | 5 | 23,865 | Steve Trachsel | Chin-hui Tsao | Steve Trachsel | Chin-hui Tsao | | 540 | 618 | -78 |
| 2003-08-19 | @ SDN | 124 | L 2-3 | 54-69 | 5 | 21,794 | Tom Glavine | Kevin Jarvis | Scott Linebrink | Mike Stanton | Rod Beck | 542 | 621 | -79 |
| 2003-08-20 | @ SDN | 125 | L 1-2 | 54-70 | 5 | 16,532 | Aaron Heilman | Jake Peavy | Rod Beck | Grant Roberts | | 543 | 623 | -80 |
| 2003-08-21 | @ SDN | 126 | W 5-1 | 55-70 | 5 | 21,958 | Jae Weong Seo | Oliver Perez | Jae Weong Seo | Oliver Perez | | 548 | 624 | -76 |
| 2003-08-22 | @ LAN | 127 | L 1-2 | 55-71 | 5 | 40,714 | Al Leiter | Hideo Nomo | Hideo Nomo | Al Leiter | Eric Gagne | 549 | 626 | -77 |
| 2003-08-23 | @ LAN | 128 | W 4-0 | 56-71 | 5 | 44,449 | Steve Trachsel | Andy Ashby | Steve Trachsel | Andy Ashby | | 553 | 626 | -73 |
| 2003-08-24 | @ LAN | 129 | W 2-1 | 57-71 | 5 | 45,496 | Tom Glavine | Kevin Brown | Tom Glavine | Kevin Brown | John Franco | 555 | 627 | -72 |
| 2003-08-26 | @ ATL | 130 | W 6-5 | 58-71 | 5 | 24,694 | Jae Weong Seo | Shane Reynolds | Jae Weong Seo | Shane Reynolds | Mike Stanton | 561 | 632 | -71 |
| 2003-08-27 | @ ATL | 131 | L 1-4 | 58-72 | 5 | 23,755 | Aaron Heilman | Greg Maddux | Greg Maddux | Aaron Heilman | Kent Mercker | 562 | 636 | -74 |
| 2003-08-28 | @ ATL | 132 | W 3-1 | 59-72 | 5 | 27,856 | Al Leiter | Mike Hampton | Al Leiter | Mike Hampton | David Weathers | 565 | 637 | -72 |
| 2003-08-29 | vs PHI | 133 | L 0-7 | 59-73 | 5 | 33,208 | Steve Trachsel | Kevin Millwood | Kevin Millwood | Steve Trachsel | | 565 | 644 | -79 |
| 2003-08-30 | vs PHI | 134 | L 2-4 | 59-74 | 5 | 26,769 | Tom Glavine | Randy Wolf | Randy Wolf | Tom Glavine | Jose Mesa | 567 | 648 | -81 |
| 2003-08-31 | vs PHI | 135 | L 1-4 | 59-75 | 5 | 26,180 | Jae Weong Seo | Vicente Padilla | Vicente Padilla | Jae Weong Seo | Jose Mesa | 568 | 652 | -84 |
| 2003-09-01 | vs ATL | 136 | W 3-2 | 60-75 | 5 | 23,877 | Jeremy Griffiths | Greg Maddux | Dan Wheeler | Trey Hodges | David Weathers | 571 | 654 | -83 |
| 2003-09-02 | vs ATL | 137 | W 3-1 | 61-75 | 5 | 24,390 | Al Leiter | Mike Hampton | Al Leiter | Mike Hampton | David Weathers | 574 | 655 | -81 |
| 2003-09-03 | vs ATL | 138 | W 9-3 | 62-75 | 5 | 16,439 | Steve Trachsel | Russ Ortiz | Steve Trachsel | Russ Ortiz | | 583 | 658 | -75 |
| 2003-09-04 | @ PHI | 139 | L 5-6 | 62-76 | 5 | 19,259 | Tom Glavine | Randy Wolf | Valerio de los Santos | Mike Stanton | | 588 | 664 | -76 |
| 2003-09-05 | @ PHI | 140 | L 0-1 | 62-77 | 5 | 26,712 | Jae Weong Seo | Vicente Padilla | Vicente Padilla | Jae Weong Seo | Rheal Cormier | 588 | 665 | -77 |
| 2003-09-06 | @ PHI | 141 | L 6-9 | 62-78 | 5 | 38,671 | Jeremy Griffiths | Brett Myers | Brett Myers | Jeremy Griffiths | Turk Wendell | 594 | 674 | -80 |
| 2003-09-07 | @ PHI | 142 | L 4-5 | 62-79 | 5 | 29,159 | Al Leiter | Amaury Telemaco | Rheal Cormier | Dan Wheeler | | 598 | 679 | -81 |
| 2003-09-08 | vs FLO | 143 | L 0-5 | 62-80 | 5 | 15,155 | Steve Trachsel | Josh Beckett | Josh Beckett | Steve Trachsel | | 598 | 684 | -86 |
| 2003-09-09 | vs FLO | 144 | L 1-3 | 62-81 | 5 | 29,410 | Tom Glavine | Carl Pavano | Ugueth Urbina | David Weathers | Braden Looper | 599 | 687 | -88 |
| 2003-09-10 | vs FLO | 145 | L 3-7 | 62-82 | 5 | 16,699 | Jae Weong Seo | Mark Redman | Mark Redman | Jae Weong Seo | | 602 | 694 | -92 |
| 2003-09-12 | @ MON | 146 | L 4-7 | 62-83 | 5 | 10,701 | Al Leiter | T.J. Tucker | T.J. Tucker | Al Leiter | Luis Ayala | 606 | 701 | -95 |
| 2003-09-13 | @ MON | 147 | W 5-4 | 63-83 | 5 | 15,086 | Steve Trachsel | Javier Vazquez | Steve Trachsel | Javier Vazquez | Grant Roberts | 611 | 705 | -94 |
| 2003-09-14 | @ MON | 148 | L 3-7 | 63-84 | 5 | 21,417 | Tom Glavine | Zach Day | Zach Day | Tom Glavine | | 614 | 712 | -98 |
| 2003-09-15 | @ CHN | 149 | L 1-4 | 63-85 | 5 | 38,698 | Jeremy Griffiths | Matt Clement | Matt Clement | Jeremy Griffiths | Joe Borowski | 615 | 716 | -101 |
| 2003-09-16 | @ CHN | 150 | L 2-3 | 63-86 | 5 | 39,534 | Jae Weong Seo | Mark Prior | Mark Prior | Jae Weong Seo | Joe Borowski | 617 | 719 | -102 |
| 2003-09-17 | @ CHN | 151 | L 0-2 | 63-87 | 5 | 38,482 | Al Leiter | Kerry Wood | Kerry Wood | Al Leiter | | 617 | 721 | -104 |
| 2003-09-18 | vs MON | 152 | L 0-1 | 63-88 | 5 | 18,914 | Steve Trachsel | Javier Vazquez | Javier Vazquez | Steve Trachsel | Chad Cordero | 617 | 722 | -105 |
| 2003-09-19 | vs MON | 153 | L 1-7 | 63-89 | 5 | 33,083 | Tom Glavine | Zach Day | Zach Day | Tom Glavine | | 618 | 729 | -111 |
| 2003-09-20 | vs MON | 154 | L 3-4 | 63-90 | 5 | 37,294 | Aaron Heilman | Livan Hernandez | Chad Cordero | Mike Stanton | Rocky Biddle | 621 | 733 | -112 |
| 2003-09-21 | vs MON | 155 | L 2-4 | 63-91 | 5 | 28,702 | Jae Weong Seo | Tomo Ohka | Luis Ayala | Grant Roberts | Rocky Biddle | 623 | 737 | -114 |
| 2003-09-23 | vs PIT | 156 | W 1-0 | 64-91 | 5 | 17,830 | Al Leiter | Kip Wells | Al Leiter | Kip Wells | | 624 | 737 | -113 |
| 2003-09-24 | vs PIT | 157 | W 5-3 | 65-91 | 5 | 22,134 | Steve Trachsel | Jeff D'Amico | Steve Trachsel | Jeff D'Amico | Mike Stanton | 629 | 740 | -111 |
| 2003-09-25 | vs PIT | 158 | L 1-3 | 65-92 | 5 | 25,081 | Tom Glavine | Salomon Torres | Salomon Torres | Grant Roberts | Julian Tavarez | 630 | 743 | -113 |
| 2003-09-26 | @ FLO | 159 | L 3-4 | 65-93 | 5 | 33,215 | Aaron Heilman | Carl Pavano | Carl Pavano | Aaron Heilman | Ugueth Urbina | 633 | 747 | -114 |
| 2003-09-27 | @ FLO | 160 | W 9-3 | 66-93 | 5 | 30,204 | Jae Weong Seo | Mark Redman | Jae Weong Seo | Michael Tejera | | 642 | 750 | -108 |
| 2003-09-28 | @ FLO | 161 | L 0-4 | 66-94 | 5 | 27,529 | Jeremy Griffiths | Dontrelle Willis | Dontrelle Willis | Jeremy Griffiths | | 642 | 754 | -112 |