He competed in Formula One races from 1970 to 1980, winning five Grands Prix. His first win came his debut season, with Ferrari, and he remained with that team until 1974. After a single season with British Racing Motors Regazzoni returned to Ferrari for a further three years. After finally leaving Ferrari, Regazzoni drove for Ensign and Shadow before moving to Williams in 1979, where he won the team's first race.
He was replaced by Carlos Reutemann at Williams for 1980 and moved back to Ensign. However, following an accident at Long Beach he was left paralyzed from the waist down; ending his career in Formula One. Regazzoni did not stop racing, however, as he competed in the Paris-Dakar rally and Sebring 12 hours using a hand controlled car during the late 1980s and early 1990s. In 1996, Regazzoni was refused entry into the World Sportscar Championship by the FIA and became a commentator for Italian TV.
He died in a car accident in Italy on December 15, 2006.