The 1966 winners and runners-up of every nation that belonged to the CONMEBOL took part in the seasonal tournament. The only exceptions were Uruguay, which had its defending champion Peñarol and league champion participate, and Brazil, whose runner-up Santos declined to play.
The tournament was divided into three rounds; the first group stage, the second group stage, and the final. The first group stage had 19 teams, divided into three groups of six, seven, and eight. The best two teams of each group qualified for the second group stage. The six teams joined Peñarol in two groups of three and four. The best team in each group qualified for the final. The champion was Racing of Argentina who beat Nacional of Uruguay.
At each stage of the tournament teams receive 2 points for a win, 1 point for a draw, and no points for a loss. If two or more teams are equal on points, the following criteria will be applied to determine the ranking in the group stage:
Sixteen teams were drawn into two groups of six and one group of five. In each group, teams played against each other home-and-away. The top two teams in each group advanced to the Second round. Peñarol, the title holders, had a bye to the next round.
^Declined to play because playing in this tournament would jeopardize their performance in their national league. [dead link]
^ abJosé Luis Pierrend, John Beuker, Pablo Ciullini and Karel Stokkermans (29 November 2012). "Copa Libertadores de América 1967". RSSSF. Retrieved 9 December 2012. (Note - source also includes individual match scores, dates and goalscorers)