The Titans said a search for a replacement would begin right away.
Munchak, who was drafted by the Houston Oilers in 1982, stayed with the team after it moved to Nashville.
He spent three seasons as head coach, compiling a 22-26 record.
The Titans were 7-6 this season after a promising 3-1 start. The team lost eight of 10 games at one point.
Munchak had expressed a desire to remain as head coach but the Titans decided to go in another direction after Munchak and Tommy Smith, the team president and chief executive officer, met Friday, the (Nashville) Tennessean said.