His other notable credits include the films Once Upon a Time in High School (2004), 71: Into the Fire (2010), The Accidental Detective (2015) and its 2018 sequel, The Divine Move 2: The Wrathful (2019), and Hitman: Agent Jun (2020), as well as the television series Big Thing (2010), Medical Top Team (2013), and Queen of Mystery (2017).

Kwon Sang-woo, the most visible example of the so-called mom-zzang (slang for "great body") movement, started his career as a fashion model in the late 1990s.

His first acting experience was in the TV drama Delicious Proposal, and for the first few years of his entertainment career, he received only minor roles on television, before making his big-screen debut in the martial arts film Volcano High (2001).

[11][12][13] Things took a turn for the better in 2010 with the box-office success of Korean War film 71: Into the Fire which Kwon reportedly did not hesitate to take on, though he again portrayed a high school student.

[14][15][16][17][18][19] His drama Big Thing about Korea's first female president (played by Go Hyun-jung) was also very popular during its run, staying atop TV charts for 11 weeks straight and ending with viewership ratings around 26%.

Based on an original story by webcomic artist Kang Full, Pained was directed by Kwak Kyung-taek in a departure from his previous macho movies.

[43][44] In 2014, he reunited with Stairway to Heaven costar Choi Ji-woo in Temptation, about a married, debt-ridden businessman who agrees to a deal with a female CEO in exchange for her "ownership" of his body.

[46] Kwon then starred in comedy film The Accidental Detective which revolves around a misfit comic book rental shop owner who becomes involved in a murder case.

[69][70] In 2006 Kwon filed a complaint against Kim Tae-chon, the godfather of Beomseobangpa (one of Korea's three major criminal gangs), for threatening him when the actor failed to keep his promise to hold a fan meeting in Japan.

Kwon and the defendant eventually came to a settlement, but prosecutors continued investigations into possible ties between kkangpae and the Japanese yakuza and Chinese crime syndicates that are looking to cash in on the Korean Wave entertainment business.

[75] In an appearance on talk show Golden Fishery hosted by Kang Ho-dong in 2009, Kwon said, "After I got married, membership in my fan cafe dwindled from 240,000 to 135,000 - it was like a stock market crash."