The Cardinals went 100-62 during the season and won the National League Central division by 11 games over the NL Wild-Card Champion and eventual NL Champion Houston Astros. In the playoffs the Cardinals swept the San Diego Padres 3 games to 0 in the NLDS. However, the Cardinals lost to the Astros 4 games to 2 in the NLCS.
The season was the last one played in Busch Memorial Stadium by the Cardinals and they moved to the new Busch Stadium the next year. The Cardinals also moved their radio broadcasts from KMOX after a 55-year affiliation to KTRS after the season. After the 2010 season, the Cardinals would move their radio broadcasts from KTRS back to KMOX, starting in 2011.
First baseman Albert Pujols won the MVP Award this year, batting .330, with 41 home runs and 117 RBIs. Chris Carpenter won the Cy Young Award this year, with a 2.83 ERA, 21 wins, and 213 strikeouts. Outfielder Jim Edmonds won a Gold Glove this year.
December 18, 2004: Dan Haren was traded by the St. Louis Cardinals with Daric Barton and Kiko Calero to the Oakland Athletics for Mark Mulder.
February 21, 2005: Bill Pulsipher was Signed as a Free Agent with the St. Louis Cardinals.
On August 4, the Cardinals announced that they had bought a 50% share of KTRS 550 AM and was leaving the longtime flagship station KMOX 1120 AM after 52 years and transferring the games to KTRS in 2006.
The Cardinals clinched their fifth National League Central division title in six years on September 17 when they beat the Cubs 5-1. The final regular season game at Busch Memorial Stadium took place on October 2, a 7-5 victory over the Cincinnati Reds. Rookie Chris Duncan hit the final regular season home run at that version of Busch Stadium.