The national championship was divided into two half-year tournaments, the Torneo Apertura and the Torneo Clausura.
Each was played on a home-and-away round-robin basis.
The winners of each would play for the national title in a playoff.
Following-season Copa Libertadores berths went to the winner of each tournament, while the runners-up played for a Copa CONMEBOL spot.
The bottom team on the aggregate table was relegated, while the eleventh place held a relegation/promotion playoff against the winner of the Segunda División (Second Division).