According to director Bernard L. Kowalski, producer Gene Corman didn't want to pay the grips the extra money for pushing the camera raft while they were filming in the Pasadena Arboretum in the water, so first Kowalski and his brother did it and later Corman put on a bathing suit and did it himself and ended up in a hospital for a few days.
The giant leeches are played by actors in sack-like suits made of thin black plastic raincoat-like material and complete with fake "suckers" sewn on.
Shot in eight days for $70,000 utilizing the same basic crew as "Night of the Blood Beast" and existing sets on the Chaplin backlot.
The music score for this film was a stock score used previously in the film Night of the Blood Beast (1958), also produced by Gene Corman, brother of Roger Corman (it can also be heard in Beast from Haunted Cave (1959)).