He first gained recognition in supporting roles in the films The Yellow Sea (2010) and Nameless Gangster: Rules of the Time (2012).

Kwak is known for starring in The Attorney (2013), Tazza: The Hidden Card (2014), The Wailing (2016), Asura: The City of Madness (2016), Steel Rain (2017), and The Man Standing Next (2020).

Kwak is known for his roles in the films The Yellow Sea (2010), Nameless Gangster: Rules of the Time (2012),[2] The Attorney (2013), The Wailing (2016),[3][4] Asura: The City of Madness (2016), Steel Rain (2017) and the television series Phantom (2012).

[5] Later in July 2022, Kwak renewed his contract with Mada Entertainment.

[6] On April 20, 2005, he mentioned on Knowing Bros that he was late for theater practice because of the Seoul Children's Grand Park elephants escape case.