The tournament was won by Olimpia, who beat Nacional 6–3 on aggregate in the final.

Despite being a former Copa Libertadores winner, Colombian side Atlético Nacional were forced to withdraw after CONMEBOL had prohibited international matches in Colombia in 1990 following allegations that a referee was threatened by six gunmen on the occasion of a match between Atlético Nacional and Vasco da Gama during the 1990 Copa Libertadores quarter-finals.

The matches were played from 18 October to 8 November.

Boca Juniors, as the title holders, entered the competition at the quarter-finals.

The matches were played from 28 November to 10 December.