Mark Aldred, who played the Russian crime boss (uncredited) was fired from his job as an English teacher in a Hong Kong primary school because the principal had discovered his role in this film. After a lengthy hearing, an industrial tribunal awarded Aldred HK$11,600 as a contract gratuity. However, it threw out his claim for around $79,000 in damages and dismissed Aldred's claims that his sacking was unlawful.
Maggie Q said in an interview that Wong Jing wanted her to star but she refused because she hated the script. So he went to Hong Kong production company Media Asia, who she was contracted with, and convinced them to make it and to cast her. When she again refused, they basically told her she had no choice. So she said she would star, but only if they did major rewrites. They agreed.
In 2002, Hong Kong was experiencing one of its worst years ever, with more people declaring personal bankruptcy than in the previous 20 years combined. The film industry wasn't just on fire, it was ashes. Producers were trying to save their bottom lines by turning out bland, international action movies they hoped to sell in the West. Almost every single one of those movies crashed and burned. Naked Weapon was Wong Jing's entry in this cinematic demolition derby, and it's the only one that emerged intact from the carnage.
Maggie Q said production started so fast that she didn't have time to train in martial arts. She requested a stunt double to handle the hardcore fight scenes, but the director refused, saying she was the star and wanted her face to be seen during every shot. She said she was terrified filming the action scenes and was shocked she wasn't severely injured.
The hotel scene at the beginning of the film is shot at the Manila Hotel in the Philippines, one of the oldest five star hotels in Asia. And the beach camp is located north of the capital, Subic.