Jeong was performing at Stand Up Live in Phoenix, Arizona, when a woman in the third row began having a seizure.
The comedian, interrupting his comedy routine, quickly jumped off stage and started helping the women by clearing the area around her. He waited with her until paramedics arrived at the scene and transported her to a local hospital.
"It was such perfect timing: Ken just jumped from the stage to help," Heather Holmberg, a nearby audience member, recently told USA Today.
"He's a very funny man but you were able to see a side of him that's very compassionate," she added.
After the paramedics arrived, the comedian continued the show, simply replying that he was "happy to be able to help" as the audience greeted him with a loud round of applause.
Jeong has played a doctor in several roles throughout his career, such as Dr. Kuni in the 2007 film "Knocked Up" and in 2015, he wrote and starred in "Dr. Ken," an ABC medical comedy.
But Jeong doesn't just play a doctor on TV, before he became an entertainer, he was a practicing doctor of internal medicine. He received his medical degree from the University of North Carolina at Chapel Hill School of Medicine in 1995.