For the next season, Hansen moved on to defending Serie A champions Juventus FC, where he was to play alongside fellow Danish Olympians John Hansen and Carl Aage Præst. As a part of his contract, Karl Aage demanded a clause to let him change clubs on a free transfer. The three Danes had a great understanding on the pitch. In his first season at Juventus, Karl Aage Hansen scored 23 goals in 34 games, making him the joint third highest goal scorer of the season. During the 1951–52 Serie A season, Karl Aage scored only 12 goals, but in his stead John Hansen stepped up, and became league top goal scorer, as Juventus won the Serie A championship. Karl Aage Hansen played an additional season with Juventus, before leaving the club on a free transfer in 1953. The Juventus leaders thought Karl Aage Hansen over the hill, and would not offer him a satisfactory contract. He played 87 games and scored 37 goals in the Serie A for Juventus.