28 years have passed since Trapper John (Pernell Roberts) was in Korea as a surgeon during the Korean War. Now, Trapper is working as the Chief of Surgery at San Francisco Memorial Hospital. Along side him are G. Alonzo Gates (Gregory Harrison), a former MASH surgeon as well; Dr. Stanley Riverside (Charles Siebert); Justin "Jackpot" Jackson (Brian Stokes Mitchell), an intern; as well as several nurses and other doctors. Here, Trapper takes his experiences from being in the line of fire, and applies them to the "calm" atmosphere of San Francisco Memorial.

After seven seasons on the air, Trapper John, M.D. made its way into history by becoming the most successful M*A*S*H spin-off.