Carpenter, who won the award for the first time in his career, beat out Rockies right-hander Ubaldo Jimenez (5-1, 1.77 ERA, 38 strikeouts) and Phillies southpaw Cliff Lee (4-1, 2.00 ERA) for the honor.
"It's nice," Carpenter said. "There are a lot of good guys out there that are throwing the ball really well including two guys on our staff, so to be that guy is nice."
The righty, who won the 2005 NL Cy Young Award, is putting together another Cy Young-caliber season. Carpenter is 15-3 with a Major League-leading 2.28 ERA on the year and has 119 strikeouts in 157 2/3 innings. His 15 wins trail only teammate Adam Wainwright, who was also considered for the award after his 1.30 ERA in August led all Major League pitchers with at least 40.0 innings pitched.
Closer Ryan Franklin, who led the Major Leagues with 11 saves, was also a candidate.
Carpenter is also a candidate for the Comeback Player of the Year award after missing nearly all of 2007 and 2008 with injuries. He then missed a month early in the season with an oblique strain but has been impressive from the start.
He has given up three earned runs or less in 21 of his 23 starts and has 119 strikeouts to go along with just 28 walks.
"I didn't know what to expect," Carpenter said of this season. "But I did believe if I got back and got healthy, I would give it every shot that I could to be as good as I once was."
And it appears that Carpenter is doing just that.
B.J. Rains is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.