The 1990 Pacific-10 Conference men's basketball tournament was played March 8–11 at the University Activity Center in Tempe, Arizona, on the campus of Arizona State University. The final game featured UCLA and Arizona, the only two teams that had won previous Pac-10 tournaments. The champion of the tournament for the third consecutive year was Arizona, which received the Pac-10's automatic bid to the NCAA tournament. The Most Outstanding Player was Jud Buechler of Arizona.