It Conquered the World (1956)

35mm film, black and white
mono, English

An American science fiction film directed by Roger Corman.

Plot Summary

An alien from a dying race of Venusians is lured to Earth by scientist Tom Anderson who harbours a grudge against almost everyone. Anderson has the alien plant devices on people including fellow scientist Paul Nelson. But Nelson survives the attempt and sets out to persuade Anderson of the errors of his ways before the alien gets to Anderson's wife…


* = uncredited

Directed by: Roger Corman
© MCMLVI [1956] by Sunset Productions
American International Pictures
Executive Producer: James Nicholson
Produced by: Roger Corman
Production Manager: Lou Place
Screenplay by: Lou Rusoff; Charles B. Griffith *
Photography: Fred E. West
Film Editor: Charles Gross
Music by: Ronald Stein
Music Editor: Jerry Irvin
Sound: Jay Ashworth
Ryder Sound Services, Inc.
Make-up: Larry Butterworth
Special Effects: Paul Blaisdell *
Property Master: Karl Brainard
Locations: Beachwood, Hollywood, Los Angeles, California, USA *; Bronson Caves, Bronson Canyon, Griffith Park, Los Angeles, California, USA *

Peter Graves (Dr Paul Nelson)
Beverly Garland (Claire Anderson)
Lee Van Cleef (Dr Tom Anderson)
Sally Fraser (Joan Nelson)
Russ Bender (Brigadier General James Pattick)
Jonathan Haze (Private Manuel Ortiz)
Dick Miller (Sergeant Neil)
Taggart Casey (Sheriff N.J. Shallert)
Paul Harbor (Floyd Mason)
Karyne Kadler (Ellen Peters)
Charles Griffith (Dr Pete Shelton)
Marshal Bradford (US Secretary Platt)
Tom Jackson (George Haskell)
David McMahn (General Carpenter)
Paul Blaisdell [the monster] *

Alternative Titles

Il conquistatore del mondo – Italy
Conquistò il mondo – Italy
It Conquered the Earth
– Denmark

Zontar the Thing from Venus (1966)

Extracts included in
Elvira, Mistress of the Dark (1988)
Invasion Earth: The are Here (1988)



  • Delirium no.25 (2020) p.10 – short review (Corman's greatest creatures by Chris Alexander)


  • American International Pictures: A Filmography by Robert L. Ottoson p.10 – credits, synopsis, review
  • Earth vs the Sci-fi Filmmakers: Twenty Interviews by Tom Weaver pp.133-148- illustrated interview with Peter Graves
  • by Walt Lee p.225 – credits