Frank Langella went on record in an interview stating that playing Skeletor was one of his favorite roles. His young son was a huge fan and was running around the house shouting "By the power of Grayskull," so he took the role for him. He wrote some of his own lines, like: "Tell me about the loneliness of good, He-Man. Is it equal to the loneliness of evil?"
Meg Foster's eyes are naturally blue/grey and with tiny pupils. She has been cast in many sci-fi/fantasy roles because of them, and jokes that she appeals to casting directors because she brings her own free special effect with her.
Mattel, the toy company that produced the original He-Man toys, ran a contest in which the grand prize was a role in the He-Man movie. The production was under a great deal of pressure to finish in time and under budget, so director Gary Goddard had to squeeze the contest winner into the shoot. The winner, Richard Szponder, is Pigboy, who hands Skeletor his staff when he returns from Earth. He was even listed in the end credits.
Skeletor's troops are robots because Mattel, which owned and produced the "Masters of the Universe" toyline, mandated early in production that He-Man couldn't kill anyone on screen.
The Throne Room set of Castle Grayskull was originally two large, adjoining sound stages. The wall between the sets was knocked down to make one gigantic sound stage. At that time, this was the largest set Hollywood had seen in over 40 years.