- Romance on the Set: John Richadson's love interest in the film is Raquel Welch. In real life, he married co-star Martine Beswick.
- Milestone Celebration: The film was promoted as Hammer's 100th production.
- What Could Have Been:
- The original draft had a carnivorous brontosaurus attack Tumak's people in the climax. The sequence was filmed, but ultimately got cut for pacing reasons. Somehow, it still made it to the film's poster and even the cover of the 2017 Blu-ray release.
- Ursula Andress was offered the role of Loana, but passed on the project due to salary demands.
Trivia / One Million Years B.C.