Dibiasi was coached by his father, Carlo Dibiasi, the Italian springboard champion from 1933 to 1936. He followed a strenuous training program, practicing 130 to 150 dives, six days a week. At the 1964 Olympic Games in Tokyo, he won a silver medal in the platform competition. At the 1968 Games in Mexico City, Dibiasi won his first gold medal in the platform. In 1972 (Munich) and 1976 (Montreal), he successfully defended his Olympic title, becoming the first athlete to win a diving event at three consecutive Games. He also won two European championships (1966, 1974) and two world championships (1973, 1975). Although Dibiasi's specialty was the platform, he also competed in the springboard event, garnering a silver medal at the 1968 Olympics and winning the European championship in 1974.