Rex Reason

Dr. Thomas Morgan

Jeff Morrow

Dr. William Barton

Leigh Snowden

Marcia Barton

Gregg Palmer

Jed Grant

Maurice Manson

Dr. Borg

James Rawley

Dr. Johnson

David McMahon

Capt. Stanley

Paul Fierro

Morteno

Lillian Molieri

Mrs. Morteno

Frank Chase

Steward

Larry Hudson

State Trooper

Ricou Browning

The Gill Man (in water)(uncredited)

Don Megowan

The Gill Man (on land)(uncredited)

George Sowards

Ranch Hand (uncredited)

John Sherwood

Director

Clifford Stine

Visual Effects

Leslie I. Carey

Sound

Robert Pritchard

Sound

Peter Berkos

Sound Editor

Robert L. Bratton

Sound Editor

George Hoagland

Sound Editor

Clifford Stine

Visual Effects Camera

Jay A. Morley Jr.

Costume Design

Roger J. Weinberg

Costume Design

Jack Kevan

Makeup Effects Designer

Arthur A. Ross

Screenplay

Arthur A. Ross

Story

William Alland

Producer

Irving Gertz

Original Music Composer

Henry Mancini

Original Music Composer

Heinz Roemheld

Original Music Composer

Maury Gertsman

Director of Photography

Edward Curtiss

Editor

Alexander Golitzen

Art Direction

Robert Emmet Smith

Art Direction

John P. Austin

Set Decoration

Russell A. Gausman

Set Decoration

Joan St. Oegger

Hairstylist

Vincent Romaine

Makeup Artist

Bud Westmore

Makeup Supervisor

Eddie Pyle

Camera Operator

Lew Swartz

Assistant Camera

Julius Rosenkrantz

Props