1990 Atlantic 10 Conference baseball tournament

The 1990 Atlantic 10 Conference Baseball Championship was held at Bear Stadium in Boyertown, Pennsylvania from May 11 through 14. The double elimination tournament featured the top two regular-season finishers from both of the league's divisions. East top seed Rutgers defeated West Virginia in the title game to win the tournament for the fourth time, earning the Atlantic 10's automatic bid to the 1990 NCAA tournament.

Seeding and format
Each division's top teams, based on winning percentage in the 16-game regular season schedule, qualified for the field. In the opening round of the four-team double-elimination format, the East Division champion played the West Division runner-up, and vice versa.

All-Tournament
West Virginia's Paul Prosser was named Most Outstanding Player, while Rutgers's Darrin Kotch was named Most Outstanding Pitcher.