Born in Barengo, Piedmont, Boniperti signed for Juventus at age 16; he had already built himself a reputation prior to this at youth level, as he scored 11 goals in one match. He could score successfully with both feet and was known for his power and tactical awareness. He played his first match for "the Old Lady" in Serie A on 2 March 1947 against A.C. Milan, which ended in a 2–1 defeat. His first goal for them in the league was three months later, against Sampdoria. Juventus ended the 1946–47 Serie A season as runners-up to local rivals Torino, Giampiero ended the season with five goals in six games to his name.