Jackie Chan (Wong Fei-Hung) nearly lost an eye when Jang Lee Hwang (Jim Ti-Sam) kicked him in the head during the final fight scene. When Hwang became aware of this, he refused to do more takes for the shot.
For many of the more athletic sequences, the 66-year-old Siu-Tin Yuen was doubled by his sons, Cheung-Yan Yuen and director Yuen Woo-Ping.
The drunken boxing style exists in real life, originating in China. In Chinese, it is called "Zui Quan" (sometimes called "Zuijuquan"). But unlike in the movie, it is dangerous to perform the art while drunk because serious injuries can occur.
Drunken Master II (1994) starring Jackie Chan is the only official follow-up. Various other films tried to cash in on the success of this film by attaching the title, but all are unofficial.
Once was the highest-grossing Chinese film in South Korea.