Pujols' typically imposing April performance included hitting eight homers while striking out only seven times.
St. Louis' seven-time All-Star first baseman accented his .337 average in April with 28 RBIs and 22 runs scored -- both figures leading the league. Pujols reached base in each of the 23 games in which he played, and knocked in his milestone 1,000th run on April 25.
Others receiving votes for the monthly award were first basemen Adrian Gonzalez (.333-9-20) of the Padres and Jorge Cantu (.365-7-22) of the Marlins, and outfielder Manny Ramirez, who sparked the Dodgers to the Majors' best record by hitting .372, with five homers and 15 RBIs.
It's the fourth time Pujols has been so honored, but the first since April 2006. He said recently that feeling healthy has contributed to his strong start. Pujols underwent surgery to move a nerve in his right elbow over the winter, and the procedure has reduced the discomfort he feels in the joint, where he has been managing an injury since 2003.
"Right now, it feels to the point where I feel pretty comfortable, pretty good about it," he said. "I'm capable to do things and I don't have to worry about laying in bed tonight seeing if my arm hurts. Those are things that I had to deal with. Right now, it feels great, so I don't want to jinx anything. Everything is feeling great."
Barden, meanwhile, was saluted for his productive versatility. He batted .385 in 21 games he divided among third base (19), shortstop and second base. His .641 slugging percentage led all NL rookies, among whom he was second with an on-base percentage of .432.
"I thought my rookie status had worn off after a couple call-ups," said Barden, who made appearances on Major League rosters in 2007 and '08. "But I guess it still counts. It's kind of cool."
Other rookies drawing support were Nationals hurler Jordan Zimmermann (2-0 with a 2.38 ERA), Rockies outfielder Dexter Fowler (.290 with nine stolen bases, including a five-bag haul on April 27 against the Padres), and Braves outfielder Jordan Schafer.