The final scene in which Caesar is giving his "equality" speech was added after the film's completion. This is why the final shot is only of Caesar's eyes and is of a grainy quality; the shot was just a cropped piece of footage from earlier in the film. Roddy McDowall was brought in the read the final lines, which were then edited into place and the film re-released.
This marked Natalie Trundy's first appearance in ape make-up. In her previous appearances in the series she appeared as a human.
The jumpsuits worn by the apes were leftover costumes from the 1964-68 Fox TV series "Voyage to the Bottom of the Sea" (1964). The Ape Management men's insignia patches and computer and electronic cabinets, all came from the Irwin Allen series, "The Time Tunnel" (1966). The large set that comprised Ape Management Center (where apes are processed and trained to become docile servants) is a re-dressed set of Adm. Matthew's office and the Triton Control complex from City Beneath the Sea (1971) (TV). Governor Breck's Ape Auction throne was first used in Taylor's spaceship in Planet of the Apes (1968). The same style chair is also used by passengers on the space-plane in "Land of the Giants" (1968).
Much of the film was shot in and around the University of California, Irvine campus, which was designed by futurist architect William L. Pereira, and was only six years old at the time of filming. Much of the production centered around the Social Science complex, which was designed by A.C. Martin & Associates and was still under construction during filming.
This is the only film from the original Planet of the Apes (1968) series of 5, that was not rated G, and the only entry released without a pre-title sequence. Reason: the opening was deemed too violent, and the producers wanted to avoid an R rating. The opening showed police on night patrol shooting an escaped ape and discovering his body covered with welts and bruises that are evidence of severe abuse. (Governor Breck and MacDonald refer to this incident in a scene that survived the final cut.) That and many other bloody images were deleted after a pre-release print was shown to a preview audience. The opening scene appears in the novelization and the comic book adaptation of the movie. On November, 2008, the Blu-Ray unrated version restored many of those graphic scenes, but not the pre-credit opening.