Ed Nelson "played" the crab monster with Beach Dickerson operating the monster's claws.

Allied Artists Pictures released this film on a double bill with Not of This Earth (1957) to many drive-in theaters with the tag line "Terrorama! Double Horror Sensation!"

Russell Johnson broke his toe while splashing around in the water during one scene. Due to the low budget of the film, director Roger Corman had a stage tech tape up Johnson's toe and immediately ordered him back in the water to finish the scene.

Paul Blaisdell was a member of Roger Corman's unofficial "stock company". He would normally build the monsters and special props for Corman's features. He turned this project down because he felt he could not do an adequate job for the money that was being offered.

The film's budget was $70,000.

It was actress Pamela Duncan's first film for Corman, followed by The Undead a month later.

David Arvedon provided the voice of Hoolar the Giant Crab.

About two minutes into the opening title sequence, the opening title musical score from the sci-fi movie World Without End (1956) is played.

Seven years later, actor Russell Johnson would be trapped on another island as co-star of the series Gilligan's Island.

Russell Johnson does the verse at the beginning. He also does a little narration in the movie.

Charles B. Griffith, the writer of this movie, also plays the part of Seaman Tate. The guy who falls out of the boat and into the water and then gets his head cut off by the Giant Crab Monster.

A scene involving two pilots was shot, but cut from the final finished film. Both of their names remained in the credits. Robin Riley and Doug Roberts both credited as Seamen.

The seaplane shown in the movie is a Douglas Dolphin.