Over thirty actors auditioned for the lead role, with William Shatner the eventual winner, though he then declined it. James Franciscus was also offered the role, but had committed himself to another (eventually unmade) series at the time.
The building they used for the overall shot of Blair General Hospital is a matte shot based on the Los Angeles County General Hospital. The Thalberg Building on the MGM lot was used for closer shots of the stairs and doorways of the hospital.
The establishing shots of Blair General Hospital in the series are from the first Dr. Kildare movie, Young Dr. Kildare (1938).