His breakout role came as the villain in gambling film Tazza: The High Rollers (2006), but it was his performance as an ex-cop turned pimp in surprise hit The Chaser (2008) that brought him acting awards and wider recognition.

Kim has since become an acclaimed actor in South Korea, with notable performances in films such as Running Turtle (2009), Jeon Woo-chi: The Taoist Wizard (2009), The Yellow Sea (2010), Punch (2011),The Thieves (2012), Hwayi: A Monster Boy (2013), The Classified File (2015), The Priests (2015), 1987: When the Day Comes (2017), Dark Figure of Crime (2018) and Escape from Mogadishu (2022).

Then in 2006, Kim had his breakthrough in Choi Dong-hoon's Tazza: The High Rollers, with audiences praising his performance in the supporting role as ruthless gambler Agwi (meaning "starving demon" in Buddhism).

He successfully portrayed the morally ambiguous character of a retired-cop-turned-pimp hunting down a serial killer who murdered the call girls due to his impotence.

[3] He transitioned from one of the finest character actors in the industry into a popular leading actor: Kim played a middle-aged man following his lifelong dream to play in a rock band in The Happy Life, a rural detective trying to capture a legendary prison breaker in Running Turtle,[4] and a rival Taoist wizard in Jeon Woo-chi.

[17][18] In 2015, Kim collaborated with director Kwak Kyung-taek in The Classified File.,[19] playing a detective cooperating with a shaman to find out and save a kidnapped girl.