The 2004 NCAA Division I men's ice hockey tournament involved 16 schools playing in single-elimination play. It began on March 26, 2004, and ended with the championship game on April 10. A total of 15 games were played. The University of Denver won its sixth national title with a 1 to 0 victory in the championship game over the University of Maine. This was the first season in which the Atlantic Hockey sent a representative to the tournament. Atlantic Hockey assumed possession of the automatic bid that had been the possession of the MAAC after it collapsed and all remaining ice hockey programs formed the new conference.