An original script draft showed more of the rapid evolution of the apes from primitive to intelligent and showed the progression of apes from pets to slaves.
The majority of the outdoor scenes were 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. Careful use of camera angles and editing made a handful of buildings and exteriors feel more like action spread across an entire city. Some exteriors and all of indoor sets were all filmed at the Fox backlot in Century City, Los Angeles.
The script opened with a fugitive ape being shot by the police. As they walked to it, the body would be revealed to be covered in open wounds and scars, showing the horrible living conditions of the slave apes. This was cut, again, for being too gruesome.
Of all the "Planet of the Apes" films (including the revivals), this one had the smallest production budget.
Writer Paul Dehn conceived the film as a simian take on the American Civil Rights movement of the time. Ironically, Dehn was English but brought an astute sensibility to the project. (Not surprisingly, the film was very popular with black audiences.)