Format
The tournament was divided into three phases. The first phase had 19 teams divided into four round-robin groups of four and one group of three (defending champions Nacional received a bye to the second phase). Each group had clubs from two different countries. The winners of each group advanced the second phase. Five teams joined the defending champions in two round-robin groups of three. The winners of each group advance to play in the finals. The winner of the finals, and tournament champions, are determined by points (two for a win, one for tie).
Read more about this topic: 1972 Copa Libertadores