In 2001, Kim made his acting debut in SBS TV Movie's and MBC Serie's Wuri's Family as bit part.

Next Year, Kim make his first acting debut in Movie The Coast Guard while still a senior, later commenting that the role of a soldier was the only one he could get without any prior experience.

[3] In 2007, Kim starred in Park Heung-sik's The Railroad, which told the story of two strangers who reveal their inner pain to each other when they are stranded at the last railway station before the Korean Demilitarized Zone.

[4][5] In spite of its poor box office performance, The Railroad found favour with critics, and Kim won the "Best Actor" award at the 25th Torino Film Festival.

[4][7] Based on a popular manhwa, the film focused on the conflict between two rival chefs, played by Kim and Im Won-hee.

To prepare for his role, Kim attended cooking classes for one and a half months, and for one crucial scene in particular he visited a slaughterhouse, receiving a big shock as he knew nothing about the slaughtering process.

[8][9] In addition, he was required to film a number of scenes with a cow, and spent some ten days acquainting himself with it—grooming it, feeding it and taking it for walks—remarking that it was "like working with a very sensitive actress".

[22] He next featured in the ensemble drama Cart, a film depict a story about contract workers in a large discount store who are faced with wrongful dismissals.

[26] In 2015, Kim starred in the period film The Treacherous, playing a tyrant king who exploits the populace for his own carnal pleasures.