The 1991 Torneo Descentralizado, the top tournament of Peruvian football, was played by 41 teams in the format of Regional Tournaments, whose winner advanced to national finals. The national champion was Sporting Cristal.
<small>*Note: The championship was suspended after 9 games until mid-July. One player Hector Mathei (Deportivo Municipal) was killed and seven other players injured in a bomb attack on a club dressing room (Deportivo Municipal vs Alianza Lima).</small>
<small>* Note: Two players and an official of the Union Minas (Central zone of the decentralized championship), were injured and a member of the coaching staff was killed when the team's bus was shot at as the squad returned from an away match. Highway robbers or terrorists were thought to be responsible. The central-zone championship, which qualified the winner for The final round, was suspended as a result.</small>
Since Sporting Cristal won both the Regional I and Regional II tournaments, they were crowned league champions without the need to play a title playoff. Instead, a runner-up playoff match had to be contested between the second-place teams from Regional I and Regional II to determine the qualifier for the 1992 Copa Libertadores.