Monster M*A*S*H
Walter "Radar" O'Reilly
Gary Burghoff as CPL Walter "Radar" O'Reilly
M*A*S*H character
Vital information
Rank: Corporal (E-4), U.S. Army
(briefly promoted to 2nd Lt. before being demoted back to Corporal)
Job/Role in Unit: Company Clerk, 4077th M*A*S*H
Hair Color: Burnt auburn
Eye Color: Grey
Height: 5'4"
Weight: 135 lbs.
Family/Personal Information
Born: 1932
Birthplace: Ottumwa, Iowa, U.S.
Nationality/Race: American
Spouse(s): Sandy (maiden name unknown; marriage annulled when she left him for another man while on their honeymoon)
Relatives/Children: Mr. O'Reilly (father; deceased)
Edna O'Reilly (mother)
Edward O'Reilly (uncle)
Jimmy (cousin)
Unnamed younger brother (died in childhood, age unknown)
Unnamed younger sister
Unnamed older brother
Unnamed older sister
Assorted aunts and uncles
First appeared in: M*A*S*H Novels
MASH (film)
Last appeared in: Good-Bye Radar: Part 2 (TV series episode)
Appeared on/or in: M*A*S*H TV Series
W*A*L*T*E*R Pilot episode
Played by: Gary Burghoff

"Radar is my informer. He's my snitch, my friend, my helper. If he could fly he'd be my falcon."

[~Hawkeye about Radar (The More I See You)]

"Walter O'Reilly. Decent, gentle. Innocent as a lamb, twice as cuddly."

[~Colonel Potter about Radar (The Foresight Saga)]

Corporal Walter Eugene "Radar" O’Reilly is a fictional character in the M*A*S*H novels, film, the television series, the television pilot W*A*L*T*E*R and two episodes of the series AfterM*A*S*H. He was played by Gary Burghoff, and was one of only two actors to play a role in the 1970 film and then reprise their role for television; the other actor was G. Wood, who portrayed General Hammond, though he was just a recurring character in season 1.

The novel establishes Radar's hometown as Ottumwa, Iowa. Radar's father, who was 63 years old when Radar was born, died when he was very young; Radar once confided in Colonel Blake that his father had a stroke the first time they played 'peek-a-boo'. He and his mother Edna continued to live on the family farm after his father's death, with his Uncle Ed helping out and serving as a father figure for Radar until he himself passed away (Good-Bye, Radar: Part 1).

It is never firmly established how many siblings Radar has, if any. In The Gun, Radar mentions a younger sister, and then a younger brother who died in childhood. In later episodes he also mentioned an older brother and sister, but the primary and prevailing implication throughout the series was that Radar was an only child.

Radar acquired his nickname because he was seemingly endowed with ESP, appearing at his CO's side before being called, anticipating his needs and even finishing his sentences. He also had super-human hearing, as he was able to hear incoming helicopters before anyone else could.

At the 4077th[]

After being turned away by the Marines because he wore glasses, Radar joined the Army in hopes of getting into the Signal Corps, but was assigned to the 4077th MASH instead. In the novel Radar volunteered for the army right after finishing high school, but in the TV series, he states that he was drafted. As a reflection of his youth, he had brought his teddy bear with him to the 4077th. He related well to and frequently spent time with the Korean villagers and orphans in the area. In season 2, Radar states that he is 19, meaning he was likely eighteen when he was drafted.

In the 1970 film, SFC Vollmer was the camp's Sergeant Major, but it was Radar who was company clerk and was invariably entrusted with everything by Colonel Blake. In the film, Radar was more of a worldly and sly individual, a clerk who carried with him at all times a pocketful of passes for any potential scam that might arise. By the time the TV series bowed, Radar's character became more naïve and trusting, but he was still adept at navigating clerical loopholes.

According to Father Mulcahy (in Period of Adjustment) Radar had a very rough start when he first became company clerk at the 4077th. He didn't know what he was doing, and drove everyone else crazy with his constant questions about how to do his job. But then after Colonel Blake took Radar under his wing, he soon improved and became an excellent clerk, often balancing out Blake's occasional silliness with his own near-magical abilities to get the unit whatever it needed. Throughout much of the series, he was more or less the glue that held the 4077th together, keeping the unit running like a well-oiled machine.

Blake and Radar grew very close, developing a father/son relationship, and it was Radar who tearfully announced Henry's death when his plane was shot down over the Sea of Japan. Radar was devastated by Blake's death and needed some time to adjust to the new commander, Colonel Potter, telling some that it was like being with his aunt. But he eventually became very close, if not closer, to Potter as well.

Radar had his enterprising moments, including:

  • Selling tickets to the men so they could take turns sneaking looks through a peephole in the nurses' showers.
  • Dismantling a jeep and mailing it home piece by piece. (Dear Dad)
  • Selling Style-Rite wing-tipped shoes to everyone in camp (The Trial of Henry Blake)

He was once conned into spending over fifty dollars for an improved writing course by mail (The Most Unforgettable Characters ), which he incorporated into his daily reports, which nearly drove Potter crazy.

Radar also had a tremendous appetite and was often seen consuming copious amounts of food; he was one of the very few in camp who liked the food served in the Mess Tent. His favorite drink is Nehi grape soda, but he was not averse to getting drunk with the others and smoking cigars, even though they made him sick.

His animals[]

Radar was very fond of animals and had a hobby of raising several during his time at the 4077th, including hamsters, guinea pigs, rabbits, and at one point a large turtle. For Potter's anniversary, Radar gave him a horse that he, Hawkeye, and B.J. rescued at Radar's request. Although Potter refers to the horse as a male during this episode, throughout the rest of the series, the horse is referred to as a mare, Sophie by name.

His Height[]

Radar's diminutive height was a frequent source of humor, with Hawkeye and the other doctors teasing him for his shortness. At one point Radar bought elevator shoes so that he could appear taller; the shoes almost made him eye level with Major Burns, but Hawkeye dissuaded him from wearing them saying "There's height that people never see; some people are ten feet tall, only their bodies don't know it".


With women[]

One of the more heavily developed themes throughout the series was Radar's fairly clumsy efforts to relate with the various women he meets. Radar was a virgin and very naive in romance, although he had a fiancée who broke up with him in the Season 1 episode Love Story. His naivete made him an occasional romantic target of the camp's nurses such as Nurse Gilbert (Bobbie Mitchell) in Dear Dad...Three and Nurse Baker (Lynne Marie Stewart) in Lt. Radar O'Reilly.

In many episodes where Radar tries to chat up a nurse, they are either not interested or something usually went wrong.

In Part 1 of Good-Bye Radar, Radar is stuck in Tokyo waiting for a plane back to Kimpo in Seoul. At the airport, he meets Lt. Patty Haven, a nurse on her way home. As they chat, he learns she's from Lancaster, Missouri, which is less than 100 miles from Ottumwa. They find they have a lot more in common, and when Radar is told it's time to board the plane, he asks to wait until the next one. But when he is ordered to board, he reluctantly bids Patty farewell, but not before promising to visit her after the war and kissing her.

With Hawkeye[]

Radar initially idolized Hawkeye and often went to him for advice about almost everything, but in Fallen Idol, after Hawkeye convinced Radar to go to Seoul to lose his virginity he came back to camp as a casualty. Overwhelmed with shock and guilt, Hawkeye spent a night binge drinking then had to run out of the OR during surgery the next day to throw up (which he never had to do before). When Radar later questioned Hawkeye about it, Hawkeye lost his temper, cursing everything about Radar before storming out. Later, when Hawkeye came back to apologize, Radar refused, and even threatened to punch Hawkeye if he ever trash-talked Iowa again. The two later reconciled at Potter's prompting, and from then on their relationship was on more of an equal footing, with Radar outgrowing his hero worship. Later, it is Hawkeye who pins Radar's Purple Heart on him and then gives him a rare salute.

In Mail Call Three, Radar is confused when his mother writes him that she now has a boyfriend. When he goes to Hawkeye about it, he accurately points out that Radar is jealous that he has to share his mother with someone else for the first time since he was a child; Hawkeye then compares Radar's situation with his own widowed father, who came to like one particular woman, but needed Hawkeye's approval so much that he broke up with her and remained alone after his mother died.

With others[]

Radar gets along well with his fellow enlisted, particularly Klinger and Igor, and also most of the officers, including both his commanders (Blake and Potter) and most of the surgeons (Hawkeye, Trapper, B.J. and Charles).

Conversely, he was often abused by Frank Burns, who called him derisive nicknames like "Pipsqueak" or "Runt", and at one point told him to keep quiet unless there was "a call for Philip Morris", which offended Radar. On numerous occasions when Frank would enter the Swamp, which he often referred to as "officers' country", when he found Radar there talking with Hawkeye or Trapper (or B.J.) Frank would often yell at him to get out, or chase him out of the tent, which never sat well with the other Swampmates.

To a different and somewhat lesser extent, Radar was also abused by Margaret who, whenever she began fuming about something or violently pining to be with her then-husband Donald, she would make Radar's office - and sometimes Radar himself - a target of convenience for her tantrums. In Margaret's defense, though, when she found out that Radar was going home she compared him to an old rag doll she once had as a kid, how she would kick it and abuse it, but then cried for days when she lost it. On Radar's last day as they were taking wounded into the OR, Margaret told him "Y'know, you're okay!" and blew a kiss goodbye to him.

Leaving the 4077th[]

In the first three seasons of M*A*S*H, Gary Burghoff appeared in every episode. After season 5, with work putting a strain on Burghoff's family life, he renegotiated his contract, agreeing to do 13 episodes per season instead of the usual 24 (during these times, the character of Radar was usually on R&R). By season 7, Gary started experiencing burnout and decided it was time to move on, despite co-star Mike Farrell trying to persuade him to stay on the grounds that his career would not recover. Because of that, the producers originally planned to end season 7 with Radar leaving, but CBS wanted instead for Gary to come back during season 8 to do a special 2-part goodbye show.

In Good-Bye Radar, news arrives that Radar's uncle Ed has died. Potter immediately arranges a hardship discharge for Radar so that he can go home and help his mother on the farm. Klinger is picked to replace Radar as company clerk, but with the unit still in dire straits without a generator, and Klinger being unable to get the hang of his new duties, Radar decides to stay on at the 4077th. Potter and Hawkeye both futilely try to make Radar see that he is making a mistake, but it takes Klinger's swindling a generator from I-Corps Supply to convince him that the camp will indeed soldier on without him. As a reflection of how he has matured over his time in Korea, he left his teddy bear behind on Hawkeye's cot, as Dr. Sidney Freedman predicted he would in War of Nerves.

Radar was referred to several times after leaving.

  • In Period of Adjustment (the first episode after Radar's departure), Peg Hunnicutt writes BJ and says that their daughter Erin saw Radar at the airport in San Francisco and called him "Daddy". BJ was crushed over the fact that it was the first time his daughter called someone "Daddy" and it wasn't him. He even confessed to being so jealous of Radar that "...I almost HATE him!"
  • In The Foresight Saga, Potter receives a letter from Radar telling how he is now a huge success, but it turns out that Radar was too embarrassed to admit that things are particularly bad, and Radar had to take up a second job along with working the farm just to make ends meet. So when a young Korean farmer lost his family, the gang sent him to Iowa to work on Radar's farm to help out.


In AfterMASH, Potter, Klinger and their families are just heading out the door to go to Radar's wedding in Ottumwa when Radar shows up at their door. He tells them that he ran off when he found out during his bachelor party that Sandy, his fiancée, cheated on him with his best friend Claude Greevy. Angered and hurt, Radar ran away to River Bend to see them, but Sandy follows Radar there and the two reconcile and marry (with Father Mulcahy officiating). His story continues in the 1984 TV pilot:


Radar, who had gone back to using his real name Walter, had failed at farming and was forced to sell the farm due to competing government subsidies and failed crops, and then sent his mother to live with her sister. While on their honeymoon in St. Louis, his wife Sandy abruptly dumps Walter for Claude Greevy. Having hit rock bottom emotionally, Walter is wandering the street and goes to a drug store to buy some sleeping pills to overdose; he plans to also buy some aspirin as "sleeping pills gimme a headache", but at the drug store he reconsiders after he is befriended by Victoria, the waitress.

His life takes an upturn when he moves in with his cousin Wendell Micklejohn, who helps Walter get a job working with him for the St. Louis Police Department. Walter's gentle manner and resourcefulness make him good at dealing with the public as he is able to resolve a conflict between two strippers, and to eventually counsel a teen boy who had pickpocketed his and Wendell's wallets; Walter finds out that the boy had been abandoned by his mother, lost his father in Korea, and lives with his grandmother, and that he had resorted to petty crime and pickpocketing just to make ends meet.

W*A*L*T*E*R was never picked up as a regular series, but the pilot was aired just once in July 1984 as a special on CBS in the Eastern and Central time zones, but not on the West Coast due to being pre-empted.

Radar's Teddy Bear[]

Radar's Teddy Bear, left behind on Hawkeye's cot when he went home.

Throughout the series, Radar was known for sleeping with a teddy bear that he brought with him from home as a comfort; in Officer of the Day he claimed that it belonged to his brother. The teddy bear became the source of many jokes throughout the series, including:

  • In The Novocaine Mutiny, it was revealed during Hawkeye's court martial that Radar's teddy bear held a large amount of money from a poker game that Major Burns (who was in command at that time) had ordered banned.
  • In Mail Call Three, B.J. wakes Radar in the middle of the night to place a call home to his wife. In his frustration, B.J. starts unknowingly slinging the teddy bear around by its neck until Radar stops him and calmly snatches it out of his hands saying, "His head isn't on too good, either!"

While a source for humor, the teddy bear also served for some very poignant moments as well:

  • In Quo Vadis, Captain Chandler, just as Captain Chandler (who now believes he is Jesus Christ) is about to be shipped out, Radar quietly comes up to him and asks him to bless what's in his bag: his teddy bear, claiming, "even though he's not real, we're very close"; Chandler blesses the bear, and then Radar himself.
  • In War Of Nerves, Radar, worried about his reliance on his teddy bear, comes to talk to Dr. Sidney Freedman about it; Sidney assures him that once he's home, chances are good that he won't need it anymore.
    • Sidney's prognosis turns out to be accurate; in Good-Bye Radar Part 2, when Radar finally goes home he leaves his teddy bear behind on Hawkeye's cot.
  • In the penultimate episode, As Time Goes By, Hawkeye added Radar's teddy bear to Margaret's time capsule, suggesting that it should "stand for all the soldiers who came over here as boys and went home as men." (It should be pointed out, though, that the teddy bear used in this episode was not the same one Radar had; Radar's was well-worn, had a plastic snout and wore a faded ascot around its neck, while the one Hawkeye held up in this episode was in much better condition, had a cloth snout and no ascot.)

Radar's teddy bear had originally been found on the set by one of the actors, and was added by the producers to symbolize Radar's youth and naïveté. The teddy bear was originally thought to have no name, but in a letter to Ken Kessler (who ran a radio show where the question of Radar's teddy bear's name was brought up), Gary Burghoff said that his teddy bear's name was Tiger.

On July 29, 2005, the teddy bear used in the series was sold at auction for $11,800.


  • Radar, like Captain Hunnicutt and Colonel Potter, is Methodist.
  • Gary Burghoff's left hand is slightly (but visibly) deformed, which would ironically make him unfit for military service. This was covered up in the series by Radar holding a prop such as a clipboard in that hand or simply putting it in his pocket.
  • According to the Muppet Wiki, Sesame Street character Big Bird has a teddy bear named Radar, named by Big Bird's performer Carroll Spinney as a tribute to Gary Burghoff and his character.
  • Radar was 18 at the start of the series, but Gary Burghoff himself was almost 30 at the time the series began. Audiences were generally fooled by his short stature, boyish appearance, and prepubescent voice. He also usually wore a hat to hide his increasingly receding hairline, as an indicator of his true age. In his final episode, Gary deliberately appeared without a hat to show his receding hair line as a symbol of him growing up.
  • Having played the character in the feature film, the television series, and two of its spin-offs, Gary Burghoff is the only actor to portray Radar. Trapper John, M.D. is the only version or spin-off of M*A*S*H in which Burghoff does not appear.
  • O'Reilly Media maintains a blog about new technologies entitled O'Reilly Radar, which has the domain name
  • With Radar's departure from the TV series, Hawkeye, Margaret, and Father Mulcahy were the only remaining characters with ties to the 1968 novel and the 1970 movie.
  • Burghoff also appeared (in drag) as Mrs. O'Reilly in one episode, albeit in a home movie sent to Radar.
  • Burghoff was also the first adult actor to appear nude from the rear on broadcast television. In The Sniper, Burgoff's towel fell off too early, revealing his bare buttocks for a noticeable amount of time.


Radar had a penchant for overusing words, especially when addressing superior officers. One such example was when he addressed Colonel Potter:

  • Radar: Uhh, excuse me, Colonel, sir...
    • Potter: Radar, you can call me 'Colonel' or 'sir'. You don't have to do both.
    • Radar: Yes, sir, Colonel.
    • Potter: That's better.
  • (at the conclusion of Abyssinia, Henry) "I have a message... Lieutenant Colonel... Henry Blake's plane... was shot down... over the Sea of Japan. It spun in. There were no survivors."
  • "Cows are people too!"
  • "Hey, we got rain here! You too? Wonder why the army ordered that?"
  • "You heard me! H-E-double toothpicks!"
  • "My doctor back home says I gotta' eat lots of greens. I have a deficiency of malnutrition."
  • "Permission to cover my 'nakedidity', sir."