Trailer
Images
 | Roddy McDowall as Cornelius |
 | Kim Hunter as Dr. Zira |
 | Bradford Dillman as Dr. Lewis Dixon |
 | Natalie Trundy as Dr. Stephanie 'Stevie' Branton |
 | Eric Braeden as Dr. Otto Hasslein |
 | William Windom as The President |
 | Sal Mineo as Dr. Milo |
 | Albert Salmi as E-1 |
 | Jason Evers as E-2 |
 | John Randolph as Committee Chairman |
 | Harry Lauter as General Winthrop |
 | M. Emmet Walsh as Aide |
 | Roy Glenn as Lawyer (as Roy E. Glenn Sr.) |
 | Peter Forster as Cardinal |
 | Norman Burton as Army Officer |
 | William Woodson as Naval Officer |
 | Tom Lowell as Orderly |
 | Gene Whittington as Marine Captain |
 | Donald Elson as Curator |
| Bill Bonds as TV Newscaster |
 | Army Archerd as Referee |
 | James Bacon as General Faulkner |
 | Ricardo Montalban as Armando |
 | John Alderman as Marine Corporal (uncredited) |
 | Alan Baxter as General (uncredited) |
 | Jack Berle as Secretary of State (uncredited) |
| Paul Bradley as Official at Briefing (uncredited) |
| Karl Bruck as German Newscaster (uncredited) |
 | Sam Chew Jr. as Undetermined (uncredited) |
| Robert Cole as Reporter (uncredited) |
 | Walker Edmiston as Talking Baby Chimp (uncredited) (voice) |
| Sig Frohlich as Spectator (uncredited) |
| James W. Gavin as Helicopter Pilot (uncredited) |
| George Golden as Official at Briefing (uncredited) |
| James Gonzalez as Official at Briefing (uncredited) |
| Joe Gray as Bodyguard (uncredited) |
 | Bob Harks as Aide (uncredited) |
 | Linda Harrison as Nova (archive footage) (uncredited) |
 | Elizabeth Harrower as Reporter at Hotel (uncredited) |
 | Shep Houghton as Bystander (uncredited) |
| Joseph La Cava as Waiter (uncredited) |
 | Robert Nichols as Reporter (uncredited) |
| Ron Pinkard as Undetermined (uncredited) |
| Janos Prohaska as Heloise (uncredited) |
| Tony Regan as Reporter at Hotel (uncredited) |
| Stephen Roberts as Gen. Brody (uncredited) |
 | Hank Robinson as Reporter (uncredited) |
 | James B. Sikking as Control Room Officer (uncredited) |
| Jack Slate as Reporter (uncredited) |
 | Arthur Tovey as Official at Briefing (uncredited) |
 | William Tregoe as Hotel Receptionist (uncredited) |
 | William Beckley as British News Anchor (uncredited) |
| Writing | |
| Pierre Boulle | Characters |
Directing | |
| Don Taylor | Director |
Art | |
| William J. Creber | Art Direction |
| Stuart A. Reiss | Art Direction |
Writing | |
| Paul Dehn | Screenplay |
Art | |
| Walter M. Scott | Art Direction |
Editing | |
| Marion Rothman | Editor |
Art | |
| Jack Martin Smith | Art Direction |
Crew | |
| Howard A. Anderson III | Special Effects Coordinator |
Production | |
| Arthur P. Jacobs | Producer |
Camera | |
| Joseph F. Biroc | Director of Photography |
Sound | |
| Jerry Goldsmith | Original Music Composer |
| Dean Vernon | Sound |
| Theodore Soderberg | Sound |
Production | |
| Frank Capra, Jr. | Associate Producer |
Sound | |
| Alexander Courage | Orchestrator |
