The idea for the film originated with a narrative treatment by Wong called A Story of Food, about a man and woman sharing secrets and noodles. Gradually, the idea evolved into In the Mood for Love after Wong made a few changes to the initial idea. Wong has expressed that 1960s Hong Kong holds a special place in his heart, since he grew up in the isolated communities of urbanite mainlanders who began to migrate from cities like Beijing and Shanghai after 1949 and the establishment of the People's Republic of China. These transplants often had very little contact with the local Cantonese in Hong Kong.
Wong emphasizes that he did not want to make a film about an affair, but rather that his aim was to make a film about the time period and explore how people would navigate the affair in the context of the traditional values espoused by Chow and Su at a time when those values are coming into question. Their values are reflected in their preoccupation with martial arts serials, which portray a mythical era of chivalry and tradition in China. Moreover, Wong was not interested in seeing Cheung and Leung invent distinct characters when they were roleplaying their unfaithful spouses; instead, Wong wanted them to roleplay as Chow and Su, to invite an even greater degree of ambiguity in the way the audience perceives them. Wong was not interested in exploring who was "right" and who was "wrong" in the affair, claiming that there are already far too many movies about affairs.
Wong achieved a great deal of the mood and atmosphere of the film through music. The repeated theme in the score was composed for the film, and the soundtrack includes a mixture of Chinese music from the first half of the 20th century, like Zhou Xuan's performance of "Age of Bloom," with western music that was popular and frequently played on Hong Kong radio stations in the sixties, like Nat King Cole's rendition of "Aquellos Ojos Verdes." Even the film's title was borrowed from the popular early 20th-century jazz number, “In the Mood for Love."
With regard to camerawork, Wong intentionally obstructs the frame to achieve a claustrophobic feel, so the audience can feel like one of the neighbors observing the two characters. Additionally, repetition in terms of music, angles, locations, and close-ups of objects emphasizes a sense of environmental stasis as the emotions and motivations of the characters gradually change.
