| Year: | 1990 |
| Conference: | Big West Conference |
| Division: | I |
| Gender: | Women's |
| Teams: | 10 |
| Arena: | Long Beach Arena |
| City: | Long Beach, California |
| Titlecount: | 4th |
| Coach: | Joan Bonvicini |
| Coachcount: | 4th |
| Mvp: | Geannine Jordan |
| Mvpteam: | UNLV |
The 1990 Big West Conference women's basketball tournament took place March 7–10, 1990. All games were held at the Long Beach Arena in Long Beach, California. won their fourth tournament title and received the conference's automatic bid to the 1990 NCAA Women's Division I Basketball Tournament.
All ten teams from the regular season standings qualified for the tournament.
The opening round featured two games, matching the eight versus nine seeds and the seven versus ten seeds. The remaining top seven teams were placed into the quarterfinal round, with teams seeded and paired based on regular-season records.