1990 West Coast Conference men's basketball tournament

The 1990 West Coast Conference men's basketball tournament was held March 3 and 4 at the Gersten Pavilion at Loyola Marymount University in Los Angeles, California. This was the fourth edition of the tournament.

During the first semi-final game on Sunday between top-seeded Loyola Marymount and #4 seed, LMU forward Hank Gathers collapsed with 13:34 left in the first half. He had just scored a dunk on an alley-oop pass from point guard Terrell Lowery that put the Lions up 25–13. He fell a short distance from Pilots point guard Erik Spoelstra, attempted to get up, but shortly after stopped breathing. Transferred to nearby Daniel Freeman Marina Hospital, Gathers was pronounced dead less than two hours later; he was 23 years old.

The game and the rest of the tournament were canceled, with regular season champion LMU awarded the WCC's berth in the 64-team NCAA tournament. Seeded eleventh in the West regional, the Lions won three games and advanced to the Elite Eight; they lost to top seed UNLV, the eventual national champion.