Obsada:

• Michael Rennie Klaatu
• Patricia Neal Helen Benson
• Hugh Marlowe Tom Stevens
• Sam Jaffe Prof. Jacob Barnhardt
• Billy Gray Bobby Benson
• Frances Bavier Mrs. Barley
• Lock Martin Gort
• Holly Bane Army Captain
• Marshall Bradford Chief of Staff
• John Brown George Barley
• John Burton British radio MC
• Wheaton Chambers Mr. Bleeker
• John Close Captain
• Frank Conroy Mr. Harley
• Eric Corrie British Soldier
• John Costello Cockney
• Marjorie Crossland Hilda
• Jack Daly Bit Man
• Lawrence Dobkin Army physician
• Jim Doyle A doctor
• Charles Evans Major general
• Edith Evanson Mrs. Crockett
• Franklyn Farnum Extra in Office Building Corridor
• Michael Ferris British Soldier
• Elizabeth Flournoy Emma, Jewelry clerk
• Grady Galloway American Radar Operator
• Bill Gentry Sentry
• Glenn Hardy Interviewer
• Sam Harris Scientific Delegate
• Harry Harvey Taxi driver
• Gabriel Heatter On sam
• Gil Herman Government agent
• John Hiestand TV Announcer on Truck
• H.V. Kaltenborn On sam
• Hassan Khayyam Indian Radio Announcer
• Harry Lauter Platoon leader
• Freeman Lusk Gen. Cutler
• George Lynn Col. Ryder
• Herbert Lytton Brigadier General
• Michael Mahoney Sentry
• David McMahon Air Force sergeant
• Tyler McVey Brady
• Harold Miller Military Officer at Pentagon Meeting
• Howard Negley Colonel
• Dorothy Neumann Margaret
• Sammy Ogg Sam
• Robert Osterloh Major White
• Gayle Pace Captain
• Drew Pearson On sam
• Ted Pearson Colonel
• House Peters Jr. MP captain
• 'Snub' Pollard Cab Driver
• John M. Reed Tank Driver
• Fay Roope Major general
• Olan Soule Mr. Krull
• Kim Spalding Army orderly
• Harmon Stevens Bit Man
• Charles Tannen Voice of Radio Announcer
• Harlan Warde Carson
• Rush Williams MP sergeant
• Carleton Young Colonel in Jeep