Wai Ka-Fai re-wrote most of the script of The Longest Nite with Johnnie To. To and Ka-Fai had the film take place in Macau based on the chaos the area was experiencing at the time of filming. Wai Ka-Fai has stated that most of The Longest Nite was directed by To. Large portions of the film were shot in Macau.
The Hong Kong title of the film translates to Dark Flowers, a slang for an underworld contract.
The Longest Nite was released in Hong Kong on January 1, 1998. The film grossed a total of HK$ 9,562,090 on its release.The Longest Nite was not a box office success in Hong Kong, which lead to Milkyway Image developing more commercial films such as Needing You... (2000).