Piranha

Bradford Dillman

Paul Grogan

Heather Menzies

Maggie McKeown

Kevin McCarthy

Dr. Robert Hoak

Keenan Wynn

Jack

Dick Miller

Buck Gardner

Barbara Steele

Dr. Mengers

Belinda Balaski

Betsy

Melody Thomas Scott

Laura Dickinson

Bruce Gordon

Colonel Waxman

Barry Brown

Trooper

Paul Bartel

Mr. Dumont

Shannon Collins

Suzie Grogan

Shawn Nelson

Whitney

Richard Deacon

Earl Lyon

Janie Squire

Barbara Randolph

Roger Richman

David

Bill Smillie

Jailer

Guich Koock

TV Pitchman

Jack Pauleson

Boy in Canoe

Eric Henshaw

Father in Canoe

Robert Vinson

Soldier

Virginia Dunnam

Girl

Diamond Farnsworth

Water-skier

Bruce Paul Barbour

Man in Boat

Robyn Ray

Screaming Woman

Mike Sullivan

Dam Guard

Jack Cardwell

Brandy

Sally Bondi

Swimming Deb (uncredited)

Eric Braeden

Dr. Robert Hoak (swimming double) (uncredited)

Joe Dante

Scuba Diver #2 (uncredited)

Amy Holden Jones

Hertz Clerk (uncredited)

Andrew G. La Marca

Scuba Diver #1 (uncredited)

John Sayles

Army Sentry (uncredited)

Phil Tippett

Scuba Diver (uncredited)