Each season of this show has a different arrangement of the theme music over the closing credits, although not every episode uses the arrangement specific to its corresponding season. For example, "Whom Gods Destroy", a third-season episode, uses the second-season arrangement of the theme. As did all episodes produced after it.
Robert Lansing is the only guest star on this series to be billed at the top of the program - just after the episode's title - rather than in the end credits. After the words, "Assignment: Earth", came, "Guest Star Robert Lansing as Mister Seven."
On some episodes, the closing credits show a still that is actually from the Star Trek blooper reel. It is a close-up of the actor who played the android body in "Return to Tomorrow, removing his latex make up. In the reel, He is shown taking it off, while an off-screen voice says "You wanted show business, you got it!"