Each character speaks their own languages. Mr. Chow speaks Cantonese, Bai Ling speaks Mandarin, and Tak speaks Japanese, even when talking to each other. Even so, they seem to understand each other perfectly.
The title of the film is supposed to be read as individual numbers, i.e. "Two Oh Four Six."
The camera points to the left side of Faye Wong's face when she cries. She has problems crying with her right eye, so Wong Kar-Wai shot her crying scenes on the left side of her face. However, there is one scene where the camera films the right side of her face on purpose.
The print for the Cannes Film Festival arrived just three hours before the delayed premiere, under police guard. It is the first film in Cannes' history to arrive so late that re-schedulings were necessary.
The title of the film refers to the last year before the 50-year period the Chinese Government promised to let Hong Kong remain as it is. Hong Kong was returned to China in 1997.