Although DC Comics tried to sue the producers for copying Superman, the show's premise is closer to that of another DC Comics character, Green Lantern, who was given a power ring by an alien to become a superhero.
William Katt said that at the start of the series he and Robert Culp had difficulties getting along and working with each other. Katt added they were able to use that to their advantage as their relationship reflected that as the one portrayed between their respective characters. Katt and Culp were able to resolve their differences and actually became good friends over the course of making the series.
Ralph's surname was changed near the end of the first season from Hinkley to Hanley because of the name's negative connection with John Hinckley (the man who shot President Ronald Reagan in an assassination attempt on March 30, 1981). Ralph's last name was changed back to Hinkley in the first episode of Season 2 ("The Two Hundred Mile an Hour Fastball"), after the furor over his name subsided. Interestingly enough, the unaired 1986 "Greatest American Heroine" pilot includes a scene in which Ralph Hinkley meets the President of the United States (who was still Ronald Reagan in real-life 1986).
In the pilot when Ralph is taken to a mental hospital wearing his super outfit, a man tells him, "That's a bad suit, Jim!" A similar line ("Say Jim, that's a bad out-FIT!") was said to Christopher Reeve in Superman (1978) movie.
Shortly after the first season ended in late Spring of 1981, the show's theme song "Believe It or Not", performed by Joey Scarbury was released as a single. The song became one of that Summer's biggest hit songs reaching Number Two on the Pop Charts in August, and spending 18 weeks in the Top 40.
Initially Pam was only to be featured in the Pilot, as a recurring gag was to be Ralph having a different girl friend in each episode. 'Connie Selleca' impressed the producers so much with her performance that she was made a regular on the series.
ABC officially canceled the series before the last four produced episodes were aired. The "lost episodes" were sold along with the rest of the series as part of its package for syndication, and later DVD collections.
Two years after the show's cancellation by ABC, NBC picked up the series and aired its reruns in a Sunday night, post-prime time time slot. This led to speculation that NBC was looking to revive the series, but their efforts only resulted in The Greatest American Heroine pilot.