Onder andere met: Roddy McDowall (Cornelius), Kim Hunter (Zira), Bradford Dillman (Dr. Lewis Dixon), Natalie Trundy (Dr. Stephanie Branton), Eric Braeden (Dr. Otto Hasslein), William Windom (President), Sal Mineo (Dr. Milo), Albert Salmi (E-1), Jason Evers (E-2), John Randolph (Chairman), Harry Lauter (General Winthrop), M. Emmet Walsh (Aide), Roy Glenn (Lawyer), Peter Forster (Cardinal), Ricardo Montalban (Armando)