Mok was recruited by the Shaw Brothers Studio and has been a major film star since the 1980s.
Mok is perhaps best known as Leung Foon in Once Upon a Time in China II, III, IV and V, after replacing Yuen Biao who was in the first film.
[3][4] In 1980s, Mok played an Interpol Agent in 1986 film Magic Crystal along with Andy Lau, Cynthia Rothrock and Richard Norton.
In 2000s, Mok played Suk Gwat in the 2004 film Love Is a Many Stupid Thing alongside Shawn Yue Man-lok.
[5][6] Mok was arrested in Beijing on Friday, 15 April 2011, for alleged drug abuse.