Trivia / The Valley of Gwangi

• California Doubling: The movie was shot in Cuenca, Spain.
• Creator Backlash: Neither the producer, Charles H. Schneer, and screenwriter, William Bast, had many fond remarks about the film years later. Schneer said it was his least favourite of the films he made with Harryhausen while Bast referred to it as a "mess" during production.
• Fake American: Israeli actress Gila Golan as American T.J. Breckenridge.
• Referenced by...:
  • Jurassic Park copied the scene where Gwangi suddenly appears from behind a hill and snatches a running ornithomimid using his mouth.
  • A clip from the movie was used in a "News Flash" game on Whose Line Is It Anyway?. Bonus points for Colin Mochrie getting the movie's title.
  • In The Twilight Zone (1985) episode "The Shadow Man", Danny Hayes watches the film on television.
  • Scooby-Doo! Legend of the Phantosaur has "ghost dinosaurs" rampaging through a desert town, and the local movie theater happens to be screening Gwangi in a double-bill with The Beast from 20,000 Fathoms.
  • In the webcomic Girl Genius, one of the oaths uttered by Zeetha the warrior princess is "By Gwangi!"
  • In the web animation Dinosauria, a poster of the film can be seen in the episode "The Last Tyrant", in the Distant Finale during the present day, showing the great impact the legacy of dinosaurs had on our minds despite their extinction.
• What Could Have Been: O'Brien's original idea for the film -to be titled The Valley Of The Mist- took place in the then-present day, had Gwangi captured in the Grand Canyon, and killed by being pushed off a cliff with a truck.