Nearly every non-lead actor or actress that worked on "Star Trek" (1966) also appeared on this show. This is probably due to both shows having been filmed at "Desilu Studios." Lead "Star Trek" (1966) performers, also guest appearing, include George Takei, William Shatner, and eventual series regular Leonard Nimoy.
Voice on Tape:
Good morning Mister Briggs.
In some episodes the tape recorder switch is shown on "rewind" instead of "play". (This is because the tape really is playing on rewind, the voiceover is edited-in afterwards).
Many episodes end with a freeze-framed pan-and-tilt shot of the IMF team's getaway vehicle, with series creator Bruce Geller's credit superimposed over the shot.