Obsada:

• John Agar Prof. Clete Ferguson
• Lori Nelson Helen Dobson
• John Bromfield Joe Hayes
• Nestor Paiva Lucas
• Grandon Rhodes Jackson Foster
• Dave Willock Lou Gibson
• Robert Williams George Johnson
• Charles Cane Police Captain
• Loretta Agar Woman on Boat
• Ricou Browning The Gill Man
• Diane DeLaire Miss Abbott, chimp trainer
• Mike Doyle Policjant
• Clint Eastwood Lab Technician
• Jack Gargan Skipper
• Charles Gibb Policjant
• Brett Halsey Pete, teen killed by Gill-Man
• Don C. Harvey Joe's Searchlight Partner
• Tom Hennesy The Gill Man (on land) / Marineland Diver
• Don House Bit
• Robert F. Hoy Charlie
• Ned Le Fevre Institute Worker
• Sydney Mason Announcer
• Robert Nelson Dr. McCuller
• Bert Stevens Man in Search Party
• Charles Victor Policjant
• Bob Wehling Joe, man with searchlight