Berman's sportscasting career began at Hartford's WVIT-TV as a weekend sports anchor. He joined ESPN in 1979, a month after its founding, and has been with the network ever since. Along with Bob Ley, he is one of ESPN's longest-tenured employees. He is currently the host of Monday Night Countdown. In 1988 and 1989, he hosted ESPN's first game show, Boardwalk and Baseball's Super Bowl of Sports Trivia.
In December 2008, the Associated Press ran a long retrospective on Berman's 30 year career with ESPN. "He is our most important person," said Norby Williamson, ESPN's vice president of production. "He is the face of ESPN," he added. Berman noted that his contract with ESPN expires on his 55th birthday, and that he does not see himself broadcasting into his 60s. In April 2010, however, ESPN extended Berman's contract for an undisclosed period of time, only noting that it was a multi-year deal.
Berman has become a strong backer of the Buffalo Bills in recent years. In an interview with Buffalo Bills reporter and play-by-play voice John Murphy on July 26, 2012, Berman acknowledged that you could call him a "Bills Booster". This sentiment is also echoed in Berman's on-air phrase, "No one circles the wagons like the Buffalo Bills."
Berman also has a series of candid moments caught on-air while on the set of "Monday Night Football" that were filmed either before production or on commercial breaks that feature the host swearing multiple times, hitting on a co-worker, and perhaps the most famous clip; a 1:30 rant on the unprofessional-ism of the studio crew. 
Berman is frequently mentioned on the website www.awfulannouncing.com, as most readers of the website have deemed his style as loud and annoying. He is currently in a race to be featured on the website's popular "Mount Rushmore of Awful Announcers," going up against other ESPN personalities Matt Millen, Skip Bayless, and Craig James. 
He is the studio host of NFL2K13.