O'Brien was athletic director at Long Beach State from 1989 to 1996 and oversaw two major moves: cutting the football program in 1991 and building the Walter Pyramid, the basketball arena which opened in 1994.[3]
During O'Brien's tenure at Temple (1996–2002), the Temple Owls' men's basketball team went 135–65 and made it to the NCAA Basketball Tournament in five of six seasons under head coach John Chaney. The team advanced to the Elite Eight in 1999 and 2001. The football team struggled and was voted out of the Big East Conference shortly before O'Brien resigned from Temple in January 2002.[4]