Umberto Lenzi, originally hired to direct, had a falling out with the producer just as production started and wanted to be taken off the film. He stated in a 1996 interview that he found the story "too similar to his earlier film
Seven Blood-Stained Orchids (1972)" and decided before shooting began that his name would not appear on the film. Screenwriter Harry Kirkpatrick, also known as
James Justice, was given the job of directing, and received sole directorial credit, though he convinced Lenzi to remain on the set in an uncredited advisory capacity throughout the entire production. For years, many horror film fans thought Harry Kirkpatrick was an alias for Lenzi, but Lenzi has stated in interviews that there really was a Harry Kirkpatrick who wrote & co-directed that film. He explained, "My contribution consisted solely of providing technical assistance.
Nightmare Beach (1989) should be considered the work of Harry Kirkpatrick."