Hrbek had his Major League debut in 1981 and hit a game winning home run in his first major league game. 1982 was his official rookie year and he played well for manager Billy Gardner and was immediately selected as an All-Star. After batting .301 with 23 home runs and 92 RBIs, Hrbek finished second in the American League Rookie of the Year vote, behind Cal Ripken, Jr.

Some of his most memorable moments were during the 1987 season. He hit a career best 34 home runs to help the Twins win the AL West. He was also instrumental in capturing the World Series Championship, as he hit a grand slam in Game 6.

In 1991 he again helped the Twins to win the World Series. This was especially memorable as the Twins finished the previous season in last place. Fans may remember him best, however, from his altercation with Ron Gant in Game 2, when it appeared that Hrbek had pulled Gant off the bag as Gant was returning to first base without a slide. The umpire called Gant out, citing forward progress would have caused Gant to step off the bag, even though most Atlanta fans claimed Hrbek's move was deliberate. The move was later nicknamed the "T-Rex Tag," after Hrbek jokingly speculated on a post-baseball career in professional wrestling using the name Tyrannosaurus Rex. When the Series moved to Atlanta, Braves fans jeered him excessively, and Hrbek received much hate mail, including a death threat. In response to playing the World Series under a death threat, Hrbek later said, "This game sucks. But it's a lot of fun."

Hrbek's offense turned stale after his home run in Game 1. In Game 7, with the score still tied 0-0 in the 8th inning, Hrbek executed a very uncommon 3-2-3 bases-loaded double play with catcher Brian Harper that saved the Twins against the Braves' biggest threat of the game. The Twins eventually won the game 1-0 in dramatic fashion, with Gene Larkin smashing a bases-loaded single to center field that scored Dan Gladden in the bottom of the 10th inning.

Hrbek was one of seven Twins to be part of both the 1987 and 1991 World Series teams. The other six were Randy Bush, Greg Gagne, Kirby Puckett, Al Newman, Gene Larkin, who made the winning hit in Game 7 of the 1991 series, and Dan Gladden, who was the runner Larkin scored with that hit.

Frequently injured (though seldom seriously), Hrbek retired after the players strike in 1994. Despite operating in the same lineup as Kirby Puckett for all but two years of his career, and his long and close association with Puckett, Hrbek's numbers never approached those of the center fielder, and it is generally agreed that his career, while long and productive, was not Baseball Hall of Fame material. In 2000, his first year of eligibility, Hrbek garnered only 5 votes, nowhere near the 5inimum threshold for continued eligibility, and is thus ineligible for the Hall of Fame unless voted in by the Veterans Committee. His first year of Veterans' Committee eligibility is 2015.

Kent Hrbek's number 14 was retired by the Twins in 1995, becoming one of only three others at the time (Harmon Killebrew, Rod Carew, and Tony Oliva) in franchise history. Hrbek was also inducted into the Minnesota Sports Hall of Fame in 1996. He was also one of few players then (which is even rarer today) who played out his entire career with only one team.

Currently, Kent Hrbek can be seen hosting an outdoor sports program on KARE TV-11 called Kent Hrbek Outdoors. Hrbek is also a perennial pitchman for Twin Cities-area HVAC company Carrier Heating and Air Conditioning. He now has a series of baseball fields named after him in his hometown of Bloomington, Minnesota. Since Kent Hrbek’s father died of ALS (Lou Gehrigs disease) in 1982, he has worked to increase awareness of the disease. Hrbek hosts an annual charity golf tournament in Minnesota to raise money for ALS research, and makes many public appearances on behalf of the cause.