Richard Carlson
Dr. David Reed
Richard Carlson
Dr. David Reed
Julie Adams
Kay Lawrence
Richard Denning
Dr. Mark Williams
Antonio Moreno
Dr. Carl Maia
Nestor Paiva
Captain Lucas
Whit Bissell
Dr. Edwin Thompson
Bernie Gozier
Zee
Henry A. Escalante
Chico
Ricou Browning
The Gill Man In Water (uncredited)
Ben Chapman
The Gill Man On Land (uncredited)
Art Gilmore
Narrator (voice) (uncredited)
Perry Lopez
Tomas (uncredited)
Sydney Mason
Dr. Matos (uncredited)
Rodd Redwing
Luis (uncredited)
James Miller
Old Man (uncredited)
Ted J. Kent
Editor
William E. Snyder
Director of Photography
Jack Arnold
Director
Harry Essex
Screenplay
Henry Mancini
Original Music Composer
Arthur A. Ross
Screenplay
Hans J. Salter
Original Music Composer
William Alland
Producer
Herman Stein
Original Music Composer
Ginger Stanley
Stunts
Jack N. Young
Stunts
Ted White
Stunts
Ethmer Roten
Musician
Russ Haverick
Assistant Director
James R. Wolfe
Driver
William Alland
Idea
Al Wyatt Sr.
Stunts
Everett Brown
Grip
Gene Poole
Stunts
Foster Thompson
Unit Manager
Robert Hickman
Makeup Artist
Ray Craddock
Sound Editor
Albert E. Kennedy
Sound Editor
Jack Kevan
Makeup Artist
Chris Mueller
Makeup Artist
Maurice Zimm
Story
Ray Jeffers
Set Decoration
Hilyard M. Brown
Art Direction
Bernard Herzbrun
Art Direction
Joan St. Oegger
Hairstylist
Bud Westmore
Makeup Artist
Russell A. Gausman
Set Decoration
Leslie I. Carey
Sound
Joe Lapis
Sound
Milton Rosen
Music
James Curtis Havens
Underwater Camera
Robert Emmett Dolan
Music
Scotty Welbourne
Still Photographer
E. Thomas Case
Makeup Artist
Polly Burson
Stunt Double
Fred Frank
Assistant Director
Joseph Gershenson
Music Director
Milicent Patrick
Creature Design
Milicent Patrick
Makeup Designer