The 1981 Torneo Descentralizado was the sixty-fifth season of Peruvian football. A total of 16 teams competed in the tournament. The season was divided into two phases. Melgar won its first national title and become the first club outside of the Lima Region to win the title.
The national league was divided into two phases. The first phase divided the sixteen teams into groups. Each team was placed into one of four groups depending on the region where the club was located. This dubbed regional tournament was contested in this season because the Peru national football team was using domestic players in preparation for the 1982 World Cup Qualifiers. In order to reduce the impact of the absence of these key players in the national league, the regional tournament was played in which the winner contested the second berth to the 1982 Copa Libertadores against the Descentralizado runner-up. The second phase of the league was the Descentralizado in which all sixteen teams competed in single league table and its winner was crowned national champion while its runner-up faced the first phase winner for the second berth of the Copa Libertadores.
The Torneo Regional was divided into 4 groups. The groups of the North, South and Central had its group winners advance to a Provincial final group where the top two advanced to the semifinals of the regional tournament. In the Metropolitan group, the top two advanced directly to the semifinals.