Mack the Knife, also known as Dr. Mack, is a 1995 Hong Kong comedy-drama film written, produced and directed by Lee Chi-ngai, based on the manga Dr. Kumahige (流氓医生) by Buronson (武論尊) and Takumi Nagaysu (ながやす巧). The film stars Tony Leung Chiu-wai (梁朝偉), Sean Lau Ching-wan (劉青雲), Alex To Tak-wai 杜德偉), Christy Chung Lai-tai (Andy Hui Chi-on (許志安), Hilary Tsui Ho-ying (徐濠縈), Eileen Tung Oi-Ling (童愛玲) and Gigi Leung Wing-kei (梁詠琪) in her debut film role.

Dr. Mack Lau (Tony) is a brilliant if somewhat seedy doctor working in the slums of Hong Kong. His old medical school buddy/rival, Dr. Roger Law (Alex), has become a celebrated surgeon, yet he still feels inferior to Mack. When their old professor, Professor Pau (吳耀漢 Richard Ng Yiu-hon) becomes sick and counsels Mack, Roger finds a way to pay his old rival back, which doesn’t mean good things for Mack. Lau Ching-Wan co-stars as a charmless cop in love with a local prostitute, Lok Mei (Eileen) and Andy Hui is a naive intern Dr. Sam So who volunteers in Mack’s clinic and ends up falling in love with bone cancer patient, Zin (Hilary).