Due to the American-led boycott of the 1980 Summer Olympics, the United States and other nations withdrew from the tournament. The 1980 Olympics marked the second time (after 1972) that the United States men's team did not win the gold medal in Olympic basketball; Yugoslavia won gold in the men's tournament and the Soviet Union in the women's competition.
A NOC may enter up to one men's team with 12 players and up to one women's team with 12 players. Automatic qualifications were granted to the host country for both events, plus the winning team at the 1978 FIBA World Championship and the gold medal winners at the 1976 Summer Olympics. The remaining spots were decided by corresponding continental qualifying tournaments for the men's competition, and in a tournament held months before the Olympic Games in Varna, Bulgaria for the women's event.
Three round-robin groups of four teams were formed, where the top two from each one advanced to the final round, and the remaining teams to the classification round.
Both the final and classification round groups consisted of another round-robin of six teams each where results between teams from the same preliminary group were carried over. The top two teams from the final round competed for the gold medal, while third and fourth places for bronze.
With the exception of the first four places, the final standings were decided by the corresponding places in each group.
Women's tournament:
One round-robin group is formed containing all six teams, where the top two compete for the gold medal, while the third and fourth places compete for the bronze medal in an additional match.
The remaining two teams finish with their group rank in the final standings.
Tie-breaking criteria:
Head to head results
Goal average (not the goal difference) between the tied teams
Goal average of the tied teams for all teams in its group
Men's tournament
Preliminary round
The top two teams from each group advance to the final round group, while the remaining teams compete for 8th through 12th places in the classification group. Hosts Soviet Union and the world champions Yugoslavia advanced undefeated to the final round. Meanwhile, qualification in Group C was closely contested between Italy, Cuba and Australia, which ended up being decided by a third tiebreaker in favor of the first two teams.
The first two places in the final round compete for the gold medal, while the third and fourth places compete for the bronze. The remaining teams' group ranking determines their positions in the final standings. The host nation failed to compete for the gold in spite of finishing the preliminary round undefeated, due to losses against the other two group leaders Yugoslavia and especially Italy, since the result from that match served as tiebreaker, giving the latter a passport to the gold medal match. The Soviet Union then won the bronze against Spain. Yugoslavia earned their first gold medal in men's basketball at this Olympic Games.
Results from Yugoslavia vs. Spain, Italy vs. Cuba and Soviet Union vs. Brazil were carried over from the preliminary round.
The women's tournament was decided in a round robin group with all six teams. The first two places competed for the gold medal, while the third and fourth places for the bronze. The remaining teams retain their group ranks for the final standings. The host nation finished the group phase undefeated and won the gold against Bulgaria. Yugoslavia would go on to win the bronze medal against Hungary.
