Dundee learned many of the strategies used to coach boxers as a pupil of Lou Stillman. A native of Philadelphia, he went to New York and later to Miami, where he opened the Fifth Street Gym.
Basilio was Dundee's first world champion, after he defeated Tony De Marco for the world welterweight crown. From there on, Dundee began receiving many young talents at his gym, helping polish some of the greatest boxers in history.
Dundee shot into national fame when Ali conquered the world Heavyweight title from Sonny Liston. Even as Ali became a member of a radical, Black muslim group during that era, he refused to let Dundee, a White man, go. Some Black Muslims, such as Elijah Muhammad, allegedly tried to pressure Ali to separate from his trainer, but Ali and Dundee respected each other mutually, and their relationship transcended their job: they became friends.
Dundee travelled around the world with Ali, and he was the key strategist in all of Ali's fights, which also included wins over Archie Moore, Floyd Patterson Joe Frazier, George Foreman, Ken Norton, and, later on, Leon Spinks.
Dundee was accused by Foreman of loosening the ring ropes before his 1974 Rumble in The Jungle fight with Ali, to help Ali win the fight, but Foreman himself has later retracted from those comments.
After Ali's retirement, Dundee saw a future, emerging star in Sugar Ray Leonard, whom he has called a smaller version of Ali. Dundee once again led Leonard to many of his biggest wins, including the defeats of Wilfred Benitez, Roberto Duran and Thomas Hearns. In Leonard's first bout with Hearns, Dundee, thinking that his protege was behind on the scorecards, quipped the now famous words Youre blowing it, son! Youre blowing it! before the start of round 13. Leonard went on to score a fourteenth round knockout win.
Dundee was enshrined in the International Boxing Hall of Fame in 1994.