Jim Phelps is the head of a super-secret government agency ("Impossible Mission"), and is often given secret anonymous covert mission to attempt; quite often they are unmasking of criminals or the rescuing of hostages. He picks his team depending on which tasks need to be done. One thing is vital on an Impossible Mission: the mission must be carried out in entire secrecy, often relying on high-tech equipment and elaborate deception.

An elite covert operations unit carries out highly sensitive missions subject to official denial in the event of failure, death or capture.
　　This 7-year series chronicled the adventures of the Impossible Mission Taskforce (IMF), a team of government spies and specialists who were assigned "impossible missions" by the unseen "Secretary". Although the cast varied over the years, the main characters included The Team Leader (Dan Briggs the first season, then Jim Phelps the other six), The Techno-Wizard (Barney Collier), The Strongman (Willy Armitage), The Master of Disguise (first Rollin Hand, then The Amazing Paris), and The Femme Fatale (Cinnamon Carter, Casey, Dana Lambert, Mimi Davis).
　　The series is best known for its opening mission assignment (conducted by a pre-recorded tape), the theme composed by Lalo Schifrin, the leader's selection of mission agents from a dossier, the opening briefing, the intricate use of disguises and a typical "mask pulloff" scene near the end of most episodes, and the relative lack of characterization of the characters.