Pernell Roberts portrayed the title character, a lovable surgeon who became a mentor and father figure in San Francisco, California.

focuses on Dr. "Trapper" John McIntyre (Pernell Roberts) 28 years after his discharge from the 4077th Mobile Army Surgical Hospital (MASH) in the Korean War.

He did not merely learn how to stop fighting the system but became a part of it, in a sense, as the Chief of Surgery at San Francisco Memorial Hospital.

New York State Supreme Court Justice Martin Stecher found that Preminger's agreement with Fox did not give him the right to produce Trapper John M.D., but did entitle him to a 25% share in profits from the show.

[2] It has sometimes been reported that the producers of the television series M*A*S*H filed suit claiming they were entitled to royalties from the new show, arguing that it was based on the character as portrayed in their series by Wayne Rogers, but the producers of Trapper John, M.D successfully argued that it was based only on the earlier film and Richard Hooker's MASH: A Novel About Three Army Doctors.