This pilot film for the popular medical drama turned out to be the only shared credit of
Edward G. Robinson, who was originally cast to play Dr. Zaius in the preceding year's
Planet of the Apes (1968), and
Maurice Evans who ended up playing the role in the finished film and its first sequel
Beneath the Planet of the Apes (1970). Test footage had even been shot with Robinson in an early version of the simian makeup, acting opposite
Charlton Heston who would be the film's star and also appear in that next installment,
Linda Harrison who would play Nova in those same two first films of the saga (in the test footage as the originally intended Zira) and
James Brolin (as the originally intended Cornelius) who would not finally appear in any of the "Apes" films although he would go on to play Dr. Steven Kiley in this series' main rival medical drama
Marcus Welby, M.D. (1969). Also present in this pilot, the original "Apes" film would also star
James Daly who would continue his role here as Dr. Paul Lochner throughout the "Medical Center" series. And another actor here,
William Windom, would appear in the third "Apes" film
Escape from the Planet of the Apes (1971) playing the President of the United States.
