Walter "Radar" O'Reilly
Radar O'Reilly
Gary Burghoff as Corp. Walter "Radar" O'Reilly
M*A*S*H character
Vital information
Rank: Corporal (E-4), U.S. Army
Job/Role in Unit: Company Clerk for the 4077th M*A*S*H
Hair Color: Burnt auburn
Eye Color: Grey
Height: 5'4"
Weight: 135 lbs.
Family/Personal Information
Birthplace: Ottumwa, Iowa, U.S.
Nationality/Race: American/Caucasian
Relatives/Children: Mrs. O'Reilly (mother)
Ed O'Reilly (uncle)
Jimmy (cousin)
Unnamed younger brother (died in childhood, age unknown)
Unnamed brother
Unnamed younger sister

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 special
Played by: Gary Burghoff
Corporal Walter Eugene "Radar" O’Reilly is a fictional character in the M*A*S*H novels, film, the television series, the television movie W*A*L*T*E*R and two episodes of the series AfterM*A*S*H. The character was portrayed by Gary Burghoff in both the film and on television — the only main cast actor from the film to reprise his role on television (the other being G. Wood, who portrayed the recurring character of General Hammond).

Early Life Edit

His father, who had been 63 when Radar was born, was deceased. Radar's mother Edna lived on the family farm and his Uncle Ed helped out on the farm and served as his father figure. The novel establishes that Radar was from Ottumwa, Iowa, and attempted to join the Marine Corps, but was turned away because he wore glasses. He then joined the Army in hopes of becoming successful in the Signal Corps, but was instead assigned as an orderly at a MASH instead. While in the novel Radar joined the army voluntarily right after finishing high school, in the TV series, he states that he was drafted.

His nickname Edit

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

In The Gun Radar explains to Major Burns that he keeps his bicycle lock key with him so his younger sister can't ride the bicycle [the chain slips off]; however, despite this, the series implies he was an only child (though in one episode, Radar did mention a younger brother who died in childhood). In another episode (Officer of the Day) Radar also mentioned another brother, who works in a retail store and was a previous owner of his teddy bear, and two episodes after that (There is Nothing Like a Nurse) he mentioned older sister, who is 37.

Character Differences (Novel/Film from TV series) Edit

In the novel and movie, Radar's character was a worldly and sneaky individual, a clerk who carried with him at all times a pocketful of passes for any potential scam that might arise. But when the TV series began, his characterization shifted into that of a naive and trusting farm boy, and cigars and strong liquor made him ill and/or dizzy. His favorite beverage was grape Nehi soda.

He also sold tickets to the male members of MASH so they could take turns sneaking looks through a peephole in the nurses' showers and also used his camera to sneak pictures of the nurses showering. He also won over $800 in poker playing with members of MASH and dismantled a jeep and smuggled it home piece by piece. He once persuaded the entire company of MASH 4077 into buying pairs of wing-tip shoes - although he was once conned into spending over $50.00 for an improved writing course by mail, which nearly drove Col. Potter crazy trying to read the daily reports. He was known for his tremendous appetite for heaping portions of meat. He was also not averse to drinking Col. Blake's brandy and smoking his cigars when the colonel was off-duty.

At the 4077th (TV series)Edit

Radar was portrayed as a very naive but very friendly young man from the Midwest.

Radar had a rough start as clerk at the 4077th, where it seemed he couldn't do anything right. The unit's commander, Lt. Col. Henry Blake, took him under his wing. Eventually, Radar became an excellent clerk, often balancing out Lt. Col. Blake's occasional silliness with his 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 Blake's death when his plane was shot down over the Sea of Japan. While Radar was devastated by Blake's death and needed some time to adjust to the new commander, Colonel Potter, he eventually became very close to Potter as well.

Radar was very fond of animals and raised several during his time at M*A*S*H, including hamsters and several rabbits. For Colonel Potter's anniversary, Radar gave him a horse that he, Hawkeye, and B.J. rescued at Radar's request. Although Col. Potter refers to the horse as a male during this episode, throughout the rest of the series, the horse is referred to by name, Sophie, a mare.

As a reflection of his very young age, he had brought his teddy bear with him to the 4077th. He related well to children 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 drafted at the age of 18.

Radar initially idolized Hawkeye, but in Fallen Idol, after Hawkeye convinced him to go to Seoul to lose his virginity but instead came back to camp as a casualty, Hawkeye, overwhelmed by shock and guilt, spent a night binge drinking then had to leave the OR the next day to throw up (which he'd never had to do before). When Radar questioned Hawkeye about this, Hawkeye angrily berated him for his naivete, his hero worship, and even his home state. Later, when Hawkeye tried to apologize, Radar would have none of it, and even threatened to punch Hawkeye if he ever said anything bad about 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.

Radar's short stature was a frequent source of humor during his tenure, with Hawkeye and the other doctors teasing him for his lack of height. At one point, Radar actually bought elevator shoes so that he could appear taller. The shoes almost made him eye level with Major Frank Burns.

Radar's given first name is revealed in the series when he asks a patient, who believes he is Jesus Christ, to bless his teddy bear. He then blesses Radar, who corrects him with "Walter."

Relationships with womenEdit

One of the 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 matters of the heart, 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 other episodes where Radar tries to chat up a nurse, they are either not interested or something usually goes wrong. In Love Story, he must hurriedly learn to fake knowledge about classical books and music in order to impress Nurse Louise Anderson. In For Want of a Boot, he secures a date with Nurse Murphy only to be thrown out. In Springtime, he becomes interested in Nurse Louise Simmons but gets more than he bargained for. Late in Season 7, Radar finally succeeds in getting a date with Lieutenant Linda Nugent when he learns to be himself.

In his second-to-last episode, Radar is stuck waiting for a plane back to Uijeongbu on his way back from a week's leave in Tokyo. At the airport, he meets Lt. Patty Haven, a nurse on her way home. As they chat, he learns she's from a town in Missouri, which isn't too far from Radar's home in Ottumwa, IA. 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. He's told to "move it or lose it", so he reluctantly bids Patty farewell, but not before promising to visit her after the war and kissing her.

Leaving M*A*S*HEdit

In the first three seasons of M*A*S*H, Gary Burghoff was in every episode of the season. After season five, doing the series became a strain on Burghoff's family life, and had his contract changed to only doing 13 episodes per season out of the usual 24 (during these times, the character of Radar was usually on R&R). By season 7, Gary started experiencing burn-out 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 didn't want to do that. Instead they wanted 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 could go home and help his mother on the farm. But when Radar sees that the unit is in dire straits because they are still without a generator, he decides that the 4077th needs him more than his mother does. Hawkeye and Potter both try to convince Radar that he is making a mistake, but it takes Klinger's swindling a generator from I-Corps supply to convince him that the 4077th will survive without him. As a reflection of how he has matured over his time in Korea, he left his teddy bear behind (as Dr. Sidney Freedman predicted he would in War of Nerves), leaving it with Hawkeye.

Radar was referred to several times after leaving. On the next episode after leaving, Peg Hunnicutt writes BJ and says that their daughter Erin saw Radar at the airport in San Francisco and called him "Daddy". BJ was devastated that the first person to be called "Daddy" by his daughter was someone else. After hard times hit the farm, Radar took up a second job, working in the town's general store, as well as working the farm. 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 the 1984 television pilot, W*A*L*T*E*R, Radar moves to St. Louis, Missouri, leaving Ottumwa, Iowa, after losing the farm to competing government subsidies and a failed crop season. After finding a place for his mother with his Aunt Lucille, he leaves the "Radar" nickname behind (now just being known as Walter O'Reilly) and joins the police department. Set in the mid-1950s in St. Louis, his gentle manner and resourcefulness make him good at dealing with the public. However, the show was never picked up as a regular series.

Teddy BearEdit

Radar's teddy bear had originally been found on the set by one of the actors. Throughout the series, Radar was known for sleeping with a teddy bear. This was added by the creators to symbolize Radar's youth and naïveté; it was also the source of several jokes throughout the series—which collectively formed a recurring joke in itself. In the second to last episode, As Time Goes By, Pierce added the teddy bear to a time capsule with several other items from the camp, including one of Henry Blake's fishing lures and a broken fan belt from a helicopter. Hawkeye said, "Let [the bear] symbolize all the boys who came over here that left as men."

Radar's 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.


  • Big Bird of Sesame Street has a teddy bear named Radar, perhaps a tribute to Radar O'Reilly's teddy bear and Radar himself.
  • 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 performed his final scene without a hat, to show his half-bald head as a symbol of him growing up.
  • 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.
  • 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 show, Hawkeye Pierce, Margaret Houlihan, and Father Mulcahy were the only remaining characters on the M*A*S*H TV series with ties to the 1968 novel and the 1970 movie.
  • Burgoff also played Mrs. O'Reilly in one episode in a home movie, dressing in drag.
  • Burgoff 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.
  • Shots of Radars/Klinger's office/bunk room show the door to the left is Colonel office and the door in the center background is the Hospital recovery room with the door to the right the entrance; the interior door to the operating room is only shown once from the office and then only for a few seconds


  • "Lt. Col. Henry Blake's plane was shot down, over the Sea of Japan. It spun in. There were no survivors."
  • "Cows are people too!"
  • "I know he [the teddy bear]'s not real, but we're very close."
  • "I'm Walter."
  • "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."
  • "You better believe it mister, or I'm dead where you stand. (points his teddy bear as if it were a gun; the sound of a gunshot is heard at the same time) My bear went off!"
  • "Permission to cover my nakedity, sir."
  • "We don't use straws in combat, fella!"
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