Lord John Roxton

Michael Rennie

Acting

Jennifer Holmes

Jill St. John

Acting

Ed Malone

David Hedison

Acting

Prof. George Edward Challenger

Claude Rains

Acting

Manuel Gomez

Fernando Lamas

Acting

Prof. Summerlee

Richard Haydn

Acting

David Holmes

Ray Stricklyn

Acting

Costa

Jay Novello

Acting

Native Girl

Vitina Marcus

Acting

Burton White

Ian Wolfe

Acting

Prof. Waldron (uncredited)

Colin Campbell

Acting

Stuart Holmes (uncredited)

John Graham

Acting

Indian Chief (uncredited)

Larry Chance

Acting

Reporter at Airport (uncredited)

Bert Stevens

Acting

Man at Airport (uncredited)

Al Bain

Acting

Guest at Zoological Institute Forum (uncredited)

Bess Flowers

Acting

Guest at Zoological Institute Forum (uncredited)

Kenner G. Kemp

Acting

Guest at Zoological Institute Forum (uncredited)

Cosmo Sardo

Acting

Guest at Zoological Institute Forum (uncredited)

Murray Pollack

Acting