HOLLYWOOD — Before comedian Ken Jeong cracked into pop-cultural consciousness as Hollywood’s newest cameo king, he didn’t crave movie stardom.

The raging Asian guy seen venting spleen and spouting invective in several of the last few years’ high-grossing gross-out comedies wasn’t even a professional joke-teller by trade.
Before a casting coup landed Jeong an enviable spot on the batting order for some of movie comedy’s heaviest hitters — Judd Apatow, Todd Phillips, Will Ferrell and Adam McKay among them — Jeong’s day job didn’t involve making people laugh at all. Unless prescribing pain medication for, say, an angry patient with a herniated disc is your idea of funny.
“I practiced internal medicine at Kaiser (hospital) in Woodland Hills (in the Los Angeles area),” Jeong said over lunch near his home in Calabasas, about 25 miles northwest of downtown Los Angeles. “Comedy was a hobby. It was like my golf. I had another life.”
But once Apatow gave him his breakthrough — a supporting part as the OB-GYN who bullies and upbraids Seth Rogen’s and Katherine Heigl’s characters through the final contractions of her pregnancy in 2007’s rom-com hit “Knocked Up” — casting agents started calling. And nearly a dozen movies later, they haven’t stopped.
With short but indelible appearances in such raunchy crowd pleasers as “Pineapple Express,” “Role Models” and “Step Brothers” to his credit, Jeong currently can be seen in “The Hangover,” which arrived in theaters Friday and was one of the weekend’s top-grossing movies. Later this year, the MD-turned-comic will appear in “Couples Retreat” with Vince Vaughn, the Will Ferrell used-car comedy “The Goods: Live Hard, Sell Hard” and the romantic comedy “All About Steve” with Sandra Bullock.
According to “Hangover” director Phillips, Jeong’s defining characteristic is his “fearlessness” — something put on prominent display in the bawdy R-rated comedy that follows friends (Bradley Cooper, Zach Galifianakis and Ed Helms) trying to piece together what happened during a Vegas bachelor party gone horribly awry. Portraying Mr. Chow, an Asian crime lord who has been inexplicably locked in the trunk of their vintage Mercedes, Jeong bursts on screen naked, swearing a blue streak and clanging a tire iron upside the leads’ heads like Barry Bonds. The idea to do full frontal was Jeong’s.
“He just comes in and crushes those little parts in films,” Phillips said. “That’s what you look for: a guy who can come in and just destroy it. He’s crazy!”
It’s hardly the career path Jeong, 39, set out for himself. The North Carolina-born Korean-American attended Duke University (major: pre-med, with a minor in drama) then attained his M.D. from the University of North Carolina. It was around that time he began going to open-mike nights at local bars and delivering his earliest stand-up routines.
“It was just goofy Asian stuff,” Jeong recalled. “Definitely high energy, but I was too afraid to say I was in medicine. I’m just an educated idiot: I took that as my persona.”
After moving to New Orleans for his medical residency, Jeong didn’t let a 90-hour workweek keep him from the comedy clubs. “It was grueling, but I had a work-hard, play-hard mentality,” he said. “Everyone has something to keep them sane outside medicine. Mine was comedy.”
After winning a comedy contest called the “Big Easy Laff Off” and completing his residency, Jeong moved to Los Angeles in 1998. Even when his medical practice took off, he never gave up his sideline and performed at such Hollywood comedy venues as the Improv and the Laugh Factory.
After he accepted small parts in NBC’s “The Office” and HBO’s “Entourage,” among other TV shows, his comedy-club exposure eventually led him to do his routine on Comedy Central and BET — and the latter appearance turned into an unexpected professional asset.
“I had a patient come in with a herniated disc,” Jeong said. “He was in a lot of pain and really combative. Then when I got in the room he was like, `Hey, you were on BET!’ and he calmed down.”
When it came time for Apatow to cast the part of Dr. Kuni, an on-call obstetrician whose bedside manner bewilders but ultimately bonds the expectant couple in “Knocked Up,” the writer-director was won over by Dr. Ken’s real-life medical experience. On-set, his largely ad-libbed diatribe — a caustic performance that is polished yet draws power from Jeong’s raw immediacy as an amateur — won him the crew’s admiration.
Moreover, Apatow gave him some advice. “He told me, ‘You’re funniest when you’re angry,’ ” Jeong said. “I’ve held onto that ever since.”
Bradley Cooper became a close friend of Jeong’s while working with him on both “The Hangover” and “All About Steve.” He describes a Dr. Jeckyll/Mr. Hyde flip-switch that Jeong activates when the cameras are rolling.
“He can drum up that anger real quick. In ‘All About Steve,’ his character lets loose on my character — it’s great stuff! I think he popped some blood vessels in his eye,” Cooper said.
“Knocked Up” proved to be a game changer for the doctor. He was offered parts in five more films upon the 2007 release and ultimately decided to put his medical career on hold.
Although he admits being star-struck working with comic stalwarts such as director McKay, Jeremy Piven and “Chappelle’s Show” writer Neil Brennan, he is most excited about a project in development. A “hybrid musical” called “Million Dollar Strong,” the movie will be based on the 2006 viral Internet sensation “What’s It Gonna Be,” featuring Jeong and his New Orleans friend Mike O’Connell as an oversexed hip-hop duo. “We have a script, and we’re doing it cheap this summer,” said Phillips, who is producing the project and plans to direct it. “It’ll be small, under the radar. There’ll be 13 songs. For Ken, it’ll be a big thing.”
In the meantime, Jeong has yet to fully hang up the stethoscope. Although not regularly practicing medicine, he’s worked a few shifts in an urgent-care unit and attended a medical conference last year to accrue the medical education credits necessary to maintain his license.
“I’ll never get the opportunity to do some movies like this again,” he said. “So if nobody has any other interest in me in show business, I’ll be like, ‘Salute. Thank you very much.’ And then I’d be very happy being a physician for the rest of my life. Except, in my office, I’d have my movie poster boards hanging up instead of diplomas.”