In a statement, Uecker's surgeon said he replaced the 75-year-old broadcaster's aortic valve, aortic root and part of his ascending aorta. He also performed a coronary bypass.
"As of 2:30 p.m., Bob is out of surgery and in the ICU," said Alfred C. Nicolosi, a cardiothoracic surgeon at Froedtert Hospital and the Medical College of Wisconsin. "We are pleased that Mr. Uecker's surgery went smoothly today."
Uecker is expected to remain in the hospital for five to seven days and his full recovery is expected to take 10 to 12 weeks.
The popular Uecker is in his 40th season broadcasting Brewers games. He also has starred in commercials and the television sitcom "Mr. Belvedere."
"On behalf of the entire Brewers organization, we are relieved to know that Bob's surgery went as planned, and we look forward to his complete and speedy recovery," Brewers chairman and principal owner Mark Attanasio said. "I know Bob appreciates just how eager Brewer fans are to hear his wit, passion, and knowledge of baseball as well as all things Milwaukee — since listening to him is such a big part of our summers. Get well, Bob."
Uecker's son, Bob Jr., said the family was "thrilled" and thanked the hospital staff.
"We also want to thank our extended family, friends and all of the fans who have expressed their concern for my father," he said. "We appreciate their thoughtful and kind wishes."
Even facing surgery, Uecker hadn't lost his trademark wit.
Addressing reporters at Miller Park on Tuesday afternoon, he opened up by joking that he called a press conference to announce that he was joining the Brewers' active roster.
Uecker said he hasn't had any pain or other symptoms, beyond occasional breathing issues during his daily swim. But his doctors have been monitoring a heart murmur, and a recent scan revealed that his problems were escalating and he needed surgery soon.
Uecker said he'll be watching and listening to games during his absence.
"Winning's great, losing's bad, and when they lose, I feel bad," Uecker said. "I hate it. I played. Well, I didn't play, but I sat around."