24 teams. European national domestic league champions, plus the then current FIBA European Champions Cup title holders only, playing in a tournament system. The Finals were a two game home and away aggregate.
*The second leg was cancelled after the Yugoslavian police refused to guarantee the safety of the Belgian team, whose members received serious threats upon arrival to Belgrade, as a result of the mysterious death of Patrice Lumumba, Prime Minister of Congo, on February 11 1961. The Soviet government, an ally to Lumumba, blamed the Belgian secret service as the instigator of his murder in the former Belgian colony, and this translated into several riots in the communist countries against the Belgian interests. Since the second leg couldn't be played, Antwerpse received a 2-0 w.o. in this game and qualified for the next round.