Southpaw Kalule won at lightweight, the British Commonwealth Games in 1974 in Christchurch and in the light welterweight championship Africa in Kampala as well as the amateur World Cup in Havana.
Kalule was established in 1976 in Denmark professional. In 1979, he beat the Olympic gold medalist Ray Seales. On 24 October 1979 he won in Japan for the WBA light middleweight title with a points victory over fifteen rounds against Masashi Kudo. After five title defenses he was challenged in the U.S. in June 1981 by Sugar Ray Leonard. The fight was initially balanced, but then he went hard in the ninth round KO.
In an attempt to regain the WBA title he lost in July 1982 against Davey Moore again prematurely. Even in a building fighting future star Mike McCallum he lost by TKO.
In 1984, he hit Lindell Holmes and 1985 European champions. The European title he defended Italy against Sumbu Kalambay on points. Both boxers were in the battle on the ground. In the second defense of the title he lost prematurely against Herol Graham and then ended his career.