In school, I was the nerd who studied a lot. If you ask anyone who went to grade school or high school with me, they’re like ‘Ken? He’s a comedian?’ Becoming a comedian really wasn’t my goal. I didn’t sit down and think, ‘I want to jump naked out of car trunks! I want to light the world on fire with my dick comedy!’ I just wanted to go to university and have a nice, respectable job.”

Talk about a detour. A model student who graduated high school at 16 and became a doctor, Jeong was still practicing medicine when he got his breakthrough role age 39. Art imitated life as he played an acerbic doctor in Judd Apatow’s Knocked Up. His scene-stealing turn brought him to the attention of Todd Phillips, who offered him a four-minute part in a new comedy starring some up-and-comers called Bradley Cooper and Zach Galifianakis. The Hangover would turn into a three-film phenomenon, and Jeong’s Leslie Chow would become an outrageous, endlessly quotable fan favourite.
While shooting the first film, the worlds of medicine and acting were again colliding – this time, in a life-shattering way. His wife, Tran, was diagnosed with a rare form of breast cancer.
“It was the worst time of my life,” Jeong admits. “I almost didn’t do The Hangover. We have twin girls who are six now but they were one at the time. I had just quit my day-job as a doctor and was asking myself, ‘What have I done, what am I doing and what the hell is going to happen?’ But my wife, who had just started responding to chemo, actually told me to do The Hangover. She said, ‘Do it, you need a release.’”
Surprisingly, the actor found playing a flamboyant Chinese gangster who violently attacks people while in the nude was just what the doctor ordered.
“It was very therapeutic to do Chow in the first movie. He had such an explosive energy, which I think mellowed during the sequels. I’m sure subconsciously I was exorcising a demon and venting my rage. I think that’s why I have such a strong affinity to The Hangover that transcends just basic career achievements. It’s deeper than that.”
Jeong’s distressing personal circumstances also helped him to cement deep friendships with his director and co-stars, who he says became his extended family.
“Todd Phillips was one of the few people who knew about Tran’s situation. He was incredible. Every day on set he’d ask how she was doing. He’d say, ‘My sister’s an oncologist so if there’s anything I can do, just say”. And on the last day of shooting, Bradley drove me home all the way from Las Vegas where we were shooting just to see Tran and visit her during chemo. By the time we shot The Hangover, Tran was two years cancer free. She came out to visit us in Thailand when we were filming. Seeing her with Todd and Bradley and Zac and Ed, it was like uniting her with this big family, who had all gotten us through a really hard time.”
Given both the personal and professional affinity Jeong feels with The Hangover films, he admits shooting the final instalment was bittersweet.
“It was the right moment to end the franchise, which is why there’s an appropriate air of finality to the last one. However, these are my friends, and that was my favourite ever role. This job and these people got me through the worst period of my life.”
As for whether we’ll see Chow returning with his own spin-off, Jeong is ebullient.
“I’d love to! Let the reign of madness continue!”

The Hangover 3 is out on DVD now.