Holmgren spent the majority of his career, which began in 1971, with AIK. His best season came in 1977–78, scoring 21 goals and 31 points in 32 games. He was then named into the SwedishAll-StarTeam in 1979, having contributed 18 assists as well as scoring 11goals for29 points. As a member of AIK, Holmgren won the Elitserienplayoff championship in 1982 and 1984 as well as the regular season championship also in 1984. Afterwards, Holmgren moved to the Allsvenskan and signed with Vallentuna BK where he scored 32 points with 17 goals to his credit. He then return to AIK for one last season before retiring in 1986.