The 1991 NCAA Division I men's basketball tournament involved 64 schools playing in single-elimination play to determine the national champion of men's NCAA Division I college basketball. It began on March 14, 1991, and ended with the championship game on April 1 in Indianapolis, Indiana. A total of 63 games were played. This tournament marked the first time a #15 seed upset a #2 seed since the tournament field expanded to 64 teams in 1985, when Richmond accomplished against Syracuse in the East region.