| 2012 NL Leaders | |||||||||||||||||
| Name | Age | Team | G | W | L | IP | TBF | H | 2B | 3B | HR | R | ER | BB | SO | ERA | RA9 |
| Wily Peralta | 23 | Milwaukee | 6 | 2 | 1 | 29.0 | 113 | 24 | 4 | 0 | 0 | 8 | 8 | 11 | 23 | 2.48 | 2.48 |
| Mike MacDougal | 35 | LA Dodgers | 7 | 0 | 0 | 5.2 | 32 | 9 | 2 | 0 | 0 | 5 | 5 | 6 | 4 | 7.94 | 7.94 |
| Bryan Morris | 25 | Pittsburgh | 5 | 0 | 0 | 5.0 | 20 | 2 | 0 | 0 | 0 | 2 | 1 | 2 | 6 | 1.80 | 3.60 |
| Yusmeiro Petit | 28 | San Francisco | 1 | 0 | 0 | 4.2 | 22 | 7 | 0 | 0 | 0 | 2 | 2 | 4 | 1 | 3.85 | 3.85 |
| Drew Storen | Washington | 37 | 3 | 1 | 30.1 | 116 | 22 | 2 | 0 | 0 | 8 | 8 | 8 | 24 | 2.37 | 2.37 | |
| Justin De Fratus | 25 | Philadelphia | 13 | 0 | 0 | 10.2 | 44 | 7 | 1 | 0 | 0 | 5 | 4 | 5 | 8 | 3.37 | 4.22 |
| Zach Duke | 29 | Washington | 8 | 1 | 0 | 13.2 | 56 | 11 | 2 | 1 | 0 | 2 | 2 | 4 | 10 | 1.32 | 1.32 |
| Brandon League | 29 | LA Dodgers | 28 | 2 | 6 | 27.1 | 108 | 17 | 3 | 0 | 0 | 7 | 7 | 14 | 27 | 2.31 | 2.31 |
| Vinnie Chulk | 34 | Milwaukee | 7 | 1 | 0 | 9.0 | 48 | 17 | 5 | 1 | 0 | 10 | 10 | 4 | 10 | 10.00 | 10.00 |
| John Ely | LA Dodgers | 2 | 0 | 2 | 2.2 | 19 | 6 | 1 | 0 | 0 | 6 | 6 | 4 | 3 | 20.22 | 20.22 | |
| Zach Putnam | 25 | Colorado | 2 | 0 | 0 | 2.0 | 9 | 3 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0.00 | 0.00 |
| Daniel Runzler | San Francisco | 6 | 0 | 0 | 3.2 | 15 | 1 | 0 | 0 | 0 | 0 | 0 | 3 | 5 | 0.00 | 0.00 | |
| Hector Ambriz | 28 | Houston | 18 | 1 | 1 | 19.1 | 83 | 14 | 5 | 0 | 0 | 9 | 9 | 11 | 22 | 4.19 | 4.19 |
| Justin Hampson | 32 | NY Mets | 13 | 0 | 0 | 10.0 | 37 | 6 | 0 | 1 | 0 | 4 | 2 | 5 | 4 | 1.80 | 3.60 |
| Chad Qualls | 34 | Pittsburgh | 17 | 2 | 1 | 13.2 | 58 | 14 | 4 | 0 | 0 | 11 | 10 | 2 | 6 | 6.58 | 7.24 |
| John Lannan | 28 | Washington | 6 | 4 | 1 | 32.2 | 144 | 33 | 7 | 2 | 0 | 15 | 15 | 14 | 17 | 4.13 | 4.13 |
| Matt Lindstrom | 32 | Arizona | 12 | 1 | 0 | 10.2 | 45 | 10 | 1 | 1 | 0 | 3 | 3 | 2 | 10 | 2.53 | 2.53 |
| Rob Scahill | Colorado | 6 | 0 | 0 | 8.2 | 33 | 7 | 2 | 0 | 0 | 1 | 1 | 3 | 4 | 1.04 | 1.04 | |
| Charles Fick | St. Louis | 2 | 0 | 0 | 1.2 | 9 | 3 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 5.39 | 5.39 | |
| Jose Mijares | 28 | San Francisco | 27 | 3 | 2 | 17.2 | 74 | 14 | 4 | 1 | 0 | 5 | 5 | 8 | 20 | 2.55 | 2.55 |
| Julio Teheran | 22 | Atlanta | 2 | 0 | 0 | 6.1 | 24 | 5 | 0 | 0 | 0 | 4 | 4 | 1 | 5 | 5.69 | 5.69 |
| Shelby Miller | St. Louis | 6 | 1 | 0 | 13.2 | 54 | 9 | 1 | 0 | 0 | 2 | 2 | 4 | 16 | 1.32 | 1.32 | |
| Steven Rodriguez | LA Dodgers | 11 | 0 | 1 | 6.2 | 26 | 3 | 0 | 0 | 0 | 1 | 1 | 4 | 6 | 1.35 | 1.35 | |
| Justin Wilson | 25 | Pittsburgh | 8 | 0 | 0 | 4.2 | 26 | 10 | 3 | 0 | 0 | 1 | 1 | 3 | 7 | 1.93 | 1.93 |
| Brian Wilson | 30 | San Francisco | 2 | 0 | 0 | 2.0 | 12 | 4 | 2 | 0 | 0 | 2 | 2 | 2 | 2 | 9.00 | 9.00 |
| Rick Vanden Hurk | Pittsburgh | 4 | 0 | 1 | 2.2 | 16 | 5 | 0 | 0 | 0 | 4 | 4 | 1 | 3 | 13.48 | 13.48 | |
| Rodrigo Lopez | 37 | Chi Cubs | 4 | 0 | 1 | 6.1 | 34 | 8 | 1 | 2 | 0 | 6 | 4 | 5 | 2 | 5.69 | 8.53 |
| Daniel Otero | San Francisco | 12 | 0 | 0 | 12.1 | 57 | 18 | 5 | 1 | 0 | 11 | 8 | 2 | 8 | 5.84 | 8.03 | |
| Travis Blackley | 30 | San Francisco | 4 | 0 | 0 | 5.0 | 25 | 7 | 0 | 2 | 0 | 6 | 5 | 2 | 2 | 9.00 | 10.80 |
| Jeurys Familia | 23 | NY Mets | 8 | 0 | 0 | 12.1 | 52 | 10 | 0 | 1 | 0 | 8 | 8 | 9 | 10 | 5.84 | 5.84 |
