Walsh was the head coach at Portland State from 1993 through 2006, succeeding Pokey Allen, who left for Boise State (after defeating the Broncos soundly in Boise in 1992). In his 14 years at Portland State, Walsh compiled a 90–68 record and guided the Vikings from a Division II program to a Division I-AA contender. Walsh's tenure at Portland State was the longest of any previous Portland State football head coach. The Vikings made the Division II playoffs in 1993, 1994, and 1995, and the I-AA playoffs in 2000.