The 1998 MAC men's basketball tournament, a part of the 1997–98 NCAA Division I men's basketball season, took place at campus sites for the quarterfinal round with the semifinals and final held at SeaGate Centre in Toledo, Ohio.
Its winner received the Mid-American Conference's automatic bid to the 1998 NCAA tournament.
It was a single-elimination tournament with three rounds and the top eight MAC teams invited to participate.
No teams received byes in the tournament.
Ball State, the MAC West Division co-champion, received the number one seed in the tournament.