MASH: A Novel About Three Army Doctors, the original novel that inspired the film MASH and TV series M*A*S*H, was written by Richard Hooker, himself a former military surgeon, and was about a fictional U.S. Mobile Army Surgical Hospital in Korea during the Korean War. It was originally published in 1968.
Hooker followed the novel with two sequels. There was also a series of ghostwritten "sequels" of rather different and lighter tone, by William Butterworth.
Radar O'Reilly, while playing poker, listens in on a conversation between Lieutenant Colonel Henry Blake and General Hamilton Hartington Hammond and announces the forthcoming arrival of two new surgeons. Captains Duke Forrest and Hawkeye Pierce share a jeep to MASH unit 4077. On the way, they also share a bottle and discover that, although they come from different parts of the U.S., they have much in common. Upon arrival, rather than report to the commanding officer, they have lunch in the mess tent, where they run into Lt. Col. Blake anyway. They are assigned to work the night shift, and billeted with Major Jonathan Hobson, a Midwestern preacher and surgeon.
The two new surgeons exhibit exceptional surgical skills and commitment to their job, and gain the respect of their colleagues. However, they become annoyed by Maj. Hobson's devotion to prayer, so they complain to Henry, who reluctantly agrees to have Maj. Hobson rebilleted. Seeing that Henry is a bit of a push-over, they also request a chest surgeon for the unit. Friction mounts between the major and the new captains. Major Hobson's prayers begin to annoy everyone and Henry arranges to have him sent stateside.
Weeks later, the new chest surgeon arrives, Captain John McIntyre. He evades everyone's attempts to get to know him, and stays hidden inside a parka stocked with cans of beer and martini olives. For days Hawkeye has a nagging feeling that he's met McIntyre before. McIntyre is a fantastic surgeon, but still won't talk to anyone until Hawkeye suddenly remembers playing football against McIntyre in college. Hawkeye introduces McIntyre to everyone as Trapper John.
The Bachelor Officers Quarters (BOQ) tent occupied by the three surgeons, known as The Swamp, becomes a popular hang-out, serving cocktails at 4. One of the regulars is Father Mulcahy, the Catholic chaplain. The boys aren't religious, but they like the Father, calling him "Dago Red" because of his red hair. However, as Duke is an avowed Protestant, he requests a Protestant chaplain. The nearest Protestant chaplain is Shaking Sammy, who lives in an engineering outfit, and is so named because he loves to shake hands. The Swampmen come to dislike him because he tends to send letters to the families of fatally wounded soldiers saying all is well. After one too many of these letters, they lash him to a wooden cross and make him believe they intend to burn him alive.
Captain Waldowski, the dentist known as the Painless Pole, who has a pool table and a poker table (open 24 hours), suddenly becomes depressed and decides to commit suicide. (He's chronically depressed and has a fit of depression every month.) Duke gives him a "black capsule" to knock him out, a mock Last Supper is arranged and everybody bids him farewell. The next day he is feeling better and ready for a game of poker.
The Swampmen begin to have personal conflicts with Captain Frank Burns, a rich, arrogant surgeon from the day shift. He trained for two years with his father, who was himself not a trained surgeon. However he considers himself a better physician, and officer, than Hawkeye, and constantly harasses enlisted men. When one of his patients dies he claims "it's either God's will or somebody else's fault." He blames Private Boone for the death of a patient, reducing Boone to tears. These actions in physical assault by Duke and then by Trapper. The arrival of the new Chief Nurse, Major Margaret Houlihan, at first restores order. However, being Regular Army, she dislikes the Swampmen and sides with Burns. Henry decides to appoint a Chief Surgeon, and the job falls to Trapper, being the best surgeon in the unit. Burns and Houlihan conclude that the Swampmen are evil and Henry their puppet. They prepare a report for Gen. Hammond and later get together in her tent, where Frank stays until 1:30 am. The next day the Swampmen tease Burns and Houlihan about their late-night meeting. Trapper John calls Houlihan "Hot Lips" and Hawkeye provokes Burns into a fight. Henry is finally forced to send Burns stateside. "Henry," Duke comments, "if I get into Hot Lips and jump Hawkeye Pierce, can I go home too?"
Ho-Jon, the Korean houseboy working in the Swamp, is drafted into the South Korean army. After being wounded, he arrives at the 4077th for treatment. After rehabilitation, he resumes his position as Swampboy. The Swampmen, who are very fond of Ho-Jon, arrange to have him sent to Hawkeye's old college. To raise funds, Trapper grows a beard, dresses up like Jesus Christ, and autographs thousands of photos which the Swampmen sell for a buck apiece.
Trapper receives orders to rush to Kokura, Japan for a medical emergency. Trapper and Hawkeye depart immediately with their golf clubs. The "emergency" turns out to be a routine operation; the anesthesiologist turns out to be "Me Lay" Marston, an old friend of Hawkeye who works at Dr. Yamamoto's Finest Kind Pediatric Hospital & Whorehouse ("Finest kind" becomes one of Hawkeye's catchphrases). The two Swampmen qualify for a golf tournament and play against a good-humoured British colonel. Trapper, still resembling Christ, attracts a lot of unwanted attention. After the tournament, they have dinner with Me Lay. Me Lay asks the boys to look at a sick baby, whom they take back to the army hospital. When the hospital's commanding officer, Colonel Merrill, tries to get in their way, he is abducted, sedated and blackmailed. Me Lay adopts the orphan baby.
Business picks up at the 4077th and Trapper and Hawkeye return immediately to find the unit overwhelmed by casualties. A constant flow of wounded soldiers pours into the hospital for two weeks and all personnel work around the clock performing operations far beyond their training. At the end of the two weeks everyone is exhausted and irritable. The unit's efficiency sags, and the tremendous loss of life begins to take its toll on the surgeons. They turn to heavy drinking and start harassing the nurses, particularly Maj. Houlihan. Fed up, she again complains to the General, who comes down on Col. Blake. The Swampmen intercede on behalf of the Colonel and smooth things over with the General.
Summer arrives and the 4077th is hot and overworked. The work slacks off and while Henry is sent to Tokyo for three weeks, Colonel Horace DeLong fills in. Col. DeLong finds Hawkeye at the poker game and demands that he start surgery on a patient in the preoperative ward. Hawkeye says that the patient is receiving blood and that he will do the surgery at 3:00am. At 2:45, while scrubbing for surgery, Hawkeye explains that the waiting period was necessary for the patient to become fit for surgery. When the Swampmen get bored, to get away for a few days they lead DeLong to believe they need psychiatric evaluation. At the 325th Evac, they escape and the psychiatrist, accompanied by Henry, finds them at Mrs. Lee's (a nearby whorehouse).
Meanwhile, General Hammond has assembled a football team composed of ringers and is making tidy profits betting on his squad with other Korean units. The Swampmen organize a team to play against Gen. Hammond's team. They tell Henry to request neurosurgeon Oliver Wendell Jones, once a pro ball player known as Spearchucker. Henry becomes the coach, certain that he'd be a better coach than Hammond. Spearchucker scouts Hammond's team and finds out the general has three pros on his team. They devise a plan to get the running back out of the game, and wear the two tackles out as early as possible. Their plan is successful and they win the game 28-24, although only by using a trick play to score the winning touchdown, and by using Radar's phenomenal hearing to eavesdrop on the opponents' tactical discussions.
Time drags for Duke and Hawkeye as they wait for their active duty deployments to expire. They start to disappear for days at a time. To keep them busy, Henry has them train the new recruits, Captains Pinkham and Russell, in the short-cuts of "meatball surgery." The recruits do well, but Capt. Pinkham's wife has a mental breakdown and he is sent home.
When the time finally comes for Duke and Hawkeye to go home, everyone crowds into The Swamp for a farewell drink. The two continue to drink and cause trouble all the way home by feigning battle fatigue to scare new recruits, impersonating chaplains to get out of working short-arm inspection and harassing an airline stewardess. They part ways in Chicago and rejoin their families.
- Corporal “Radar” O'Reilly - from Ottumwa, Iowa, given his nickname for his extremely acute hearing and apparent extra-sensory perception
- Brigadier General Hamilton Hartington Hammond - stationed in Seoul
- Lieutenant Colonel Henry Braymore Blake - Commanding Officer, florid, balding, stutters when angry
- Captain Walter Koskiusko “The Painless Pole” Waldowski - from Hamtramck, Michigan, Dental Officer
- Captain Augustus Bedford “Duke” Forrest - from Forrest City, Georgia, age 29, under 6 feet tall, red hair, blue eyes, married with two daughters
- Captain Benjamin Franklin “Hawkeye” Pierce - from Crabapple Cove, Maine, age 28, over 6 feet tall, brown-blond hair, wears glasses, married with two sons, six brothers
- Major Jonathon Hobson - age 35, general practitioner from the Midwest, committed Protestant preacher, extremely unskilled as a surgeon
- Captain “Trapper” John Francis Xavier McIntyre - from Boston, Massachusetts, Chief Surgeon, very skilled at thoracic surgery
- Captain “Ugly” John Black - chief anesthesiologist, limpid-eyed, dark-haired, handsome
- Father John Patrick “Dago Red” Mulcahy - from San Diego, California, Catholic chaplain, red hair
- “Shaking” Sammy - Protestant chaplain from nearby engineering unit, loves to shake hands, tends to send letters to the families of fatally wounded soldiers saying all is well
- Sergeant “Mother Divine” - from Brooklyn, New York, mess tent cook, sells fake deeds to public landmarks to gullible soldiers
- Captain Frank Burns - from Fort Wayne, Indiana, born to affluence, accustomed to authority, adept at cardiac massage, but inept at everything else
- Private Lorenzo Boone - age 19, bumbling medical assistant
- Major Margaret “Hot Lips” Houlihan - Chief Nurse, Regular Army, blondish, fortyish
- Ho-Jon - from Seoul, age 17, houseboy and medical assistant, tall, thin, bright, Christian
- Dr. James Lodge - from Crabapple Cove, Maine, Dean of Androscoggin College
- Benjamin Franklin “Big Benjy” Pierce, Sr. - from Crabapple Cove, Maine, lobster fisherman, Hawkeye's father
- Colonel Ruxton P. Merrill - Commanding Officer, 25th Station Hospital, Kokura, Japan, an unimaginative martinet
- Captain Ezekiel Bradbury “Me Lay” Marston IV - from Spruce Harbor, Maine, anesthesiologist, Hawkeye's childhood friend
- Colonel Cornwall - British officer
- Captain Bridget “Knocko” McCarthy - nurse from Boston, Massachusetts, age 35, 5'8”
- Sergeant Pete Rizzo - medical assistant, athletic
- Dr. R. C. “Jeeter” Carroll - from Oklahoma, surgeon, not very intelligent, 5'8”, 150 lbs.
- Roger “the Dodger” Danforth - surgeon, 6073rd MASH, trained with Ugly John
- Colonel Horace DeLong - visiting officer, surgeon
- Lieutenant Rafael Rodriguez - medic, Colonel Blake's secretary
- Major Haskell - Chief of Psychiatry, 325th Evac
- Sergeant Vollmer - from Nebraska, Supply sergeant
- Captain Oliver Wendell “Spearchucker” Jones - from New Jersey, neurosurgeon, played football for the Philadelphia Eagles, also threw javelin as a track athelete
- Captain Emerson Pinkham - surgeon, Ivy League, book-smart but somewhat dense, has a wife who goes insane and is sent to an asylum
- Captain Leverett Russell - surgeon, Ivy League, book-smart but somewhat dense