2003–04 Idaho Vandals men's basketball team

The 2003–04 Idaho Vandals men's basketball team represented the University of Idaho during the 2003–04 NCAA Division I men's basketball season. Members of the Big West Conference, the Vandals were led by third-year head coach Leonard Perry and played their home games on campus at Cowan Spectrum in Moscow, Idaho.

The Vandals were 13–15 overall in the regular season and 9–9 in conference play, fourth in the standings.

Idaho met fifth seed UC Riverside in the quarterfinal of the conference tournament in Anaheim and defeated the Highlanders for their first-ever victory in the Big West tourney. The following night in the semifinal, they lost to second-seed Pacific by six points.

Postseason results
!colspan=5 style=| Big West tournament