The world is shocked by the appearance of three talking chimpanzees, who arrived mysteriously in a spacecraft. Intrigued by their intelligence, humans use them for research - until the apes attempt to escape.
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
