Production

Wong's plan to make a film set primarily in Hong Kong did not simplify matters when it came to the shoot. The city's appearance had much changed since the 1960s, and Wong's personal nostalgia for the time added to his desire for historical accuracy. Wong had little taste for working in studio settings, let alone using special effects to imitate the look of past times. Christopher Doyle later discussed the necessity of filming where the streets, the buildings, and even the sight of clothes hanging on lines (as in 1960s Hong Kong) could give a real energy to the actors and the story, whose outlines were constantly open to revision as shooting progressed. While set in Hong Kong, a portion of the filming (like outdoor and hotel scenes) was shot in less modernized neighborhoods of Bangkok, Thailand. Further, a brief portion later in the film is set in Singapore (one of Wong's initial inspirations on the story had been a short story set in Hong Kong, "Intersection," by the Hong Kong writer Liu Yichang). In its final sequences, the film also incorporates footage of Angkor Wat, Cambodia, where Leung's character is working as a journalist.

The film took 15 months to shoot. The actors found the process inspiring but demanding. They required a lot of work to understand the times, being slightly younger than Wong and having grown up in a rapidly changing Hong Kong or, in Maggie Cheung's case, partly in the United Kingdom.

The cinematographer Christopher Doyle, for whom the film was the sixth collaboration with Wong Kar-wai, had to leave when production went over schedule and was replaced by Mark Lee Ping Bin, renowned for his work with Taiwanese filmmaker Hou Hsiao-hsien. Both DPs are credited equally for the final film. Some scenes in the final cut are thought to have been shot by each, with some critics noting differences between Doyle's more kinetic style as seen in earlier Wong movies, and the more subtle long shots of Lee framing key parts of "In the Mood for Love."

The final months of production and post-production on "In the Mood for Love," a submission to the Cannes Film Festival in May 2000, were notorious for their confusion. The film was barely finished in time for the festival, as would occur again four years later when Wong submitted "2046." Wong continued shooting more and more of "In the Mood for Love" with the cast and crew as he worked furiously to edit the massive amounts of footage he had shot over the past year. He removed large chunks of the story to strip it down to its most basic element, the relationship between these characters in the 1960s, with brief allusions to earlier and later times. In the meantime, Wong screened brief segments before the festival for journalists and distributors. Despite the general lack of commercial interest in Chinese cinema at the time by North American media corporations, Wong was given a distribution deal for a limited theatrical release in North America on USA Films, based only on a few minutes of footage.