In a 2004 interview Catherine Deneuve revealed that making the film "wasn't a terribly positive experience" for her. She felt that Luis Buñuel had been isolated from the actors by the producers, and there had been a breakdown in communication as a result. She felt "very exposed in every sense of the word," she said, "but very exposed physically, which caused me distress; I felt they showed more of me than they'd said they were going to...There were moments when I felt totally used. I was very unhappy."
One scene in the film that audiences obsessed over was the one in which an Asian client entered the brothel with a mysterious box containing an unknown object that is never revealed. When he opens the box to show the prostitutes what is inside, Séverine is the only one who agrees to an encounter while the others turn away in horror. Luis Buñuel found that the most common question people asked him about the film later concerned the contents of the box. It was a question he found "senseless...I can't count the number of times people (particularly women) have asked me what was in the box, but since I myself have no idea, I usually reply, 'Whatever you want there to be.'"
The comment by Pierre Serizy, "Semen retentum venenum est" is in Latin, and could be roughly translated as "To retain one's semen is poisonous" or "To retain one's semen will allow it to eat away at one like a poison."
"Belle de jour" is a day lily in French, a flower that blooms only by day, as Severine is available only during the afternoons. "Belle de jour" is also a sort of pun, as it reminds us of "belle de nuit", an euphemism for prostitute.
Luis Buñuel shot the opening sequence outdoors near a country estate. It was during the very first day of shooting this opening sequence that Buñuel heard about some complaints from his actors. "An assistant came over to tell me the actors wanted to talk to me," said Buñuel. It concerned the syrupy dialogue between Pierre and his bride Séverine before the violent sexual attack. "Sorel had crossed out his lines and had written 'his' dialogue over them," Buñuel continued. "'What have you done?' I asked him. Very politely, he said, 'Excuse me, sir, doesn't this seem ridiculous to you?' 'Yes,' I told him, 'but don't you know what happens afterwards? After this banal dialogue, you begin to beat her with a whip, to drag her through the mud. Just deliver it as it is written.' And that's how he said it."
The film also generated a great deal of discussion and debate among audiences about its meaning and what scenes were real versus being part of Séverine's fantasies. Luis Buñuel, as usual, didn't feel the need to explain his work, which only added to the film's mystique. This blurring of reality and fantasy, he said, was "what stimulated me to film the story. By the end, the real and the imaginary fuse. I myself cannot tell you what is real and what's imaginary in the film. For me they form the same thing."
Luis Buñuel knew that Catherine Deneuve was unhappy, but he felt that it was mostly because she didn't understand his working style and the reasons behind his choices. "She didn't want her breasts to be seen," he recalled, "and the hairdresser put a strip of fabric around her. She had to appear nude for a moment, putting on a stocking to keep her breasts from being seen during that movement, she bound them up in a taffeta band."
Before the film was released, Luis Buñuel was pressured to make some cuts for the censors, which he later came to regret. "The Hakims told me, 'By letting the censors cut one thing, you keep them from cutting even more,'" said Buñuel. He was especially bothered to have to cut the scene between Séverine and the Duke (Georges Marchal). Originally, the scene had Séverine lying in a coffin in a private chapel after a Mass with a "splendid" copy of one of Grünewald's Christ paintings clearly visible on the wall. "The suppression of the Mass," he said, "completely changes the character of this scene." The scene, he said, "had more value with the painting of the Grünewald Christ, which is the most terrible image of Christ...It was painted in a ferociously realistic style. This image was important because it prepared the audience for the next scene." An edited version of the scene stayed in the film, but to Buñuel, it lacked the same impact without the original imagery.
Following its initial release, the film wasn't seen again for many years due to some rights issues with the Hakim brothers' estate. The absence of the film from circulation--including home video--for so long only helped build up its mystique for a new generation who had not yet seen it.
Martin Scorsese, a longtime fan of the film, helped spearhead the effort to get it a limited high profile release in 1995 through Miramax Zoë, a subsidiary company created by Miramax to acquire and distribute French films in the U.S. As a result, the film found itself in the spotlight once again and soon became easily available to be discovered and appreciated by new generations.
As he often did when he completed a film, Luis Buñuel claimed after 40+ years of filmmaking that his latest work would be his last. "No more cinema for me--not in Spain, not in France, nowhere," he said at the time. "Belle de Jour is my last film." As was also his habit as a driven and inspired artist, his words went out the window as he was back at work in no time on his next film, The Milky Way (1969).
While the film was shooting, Catherine Deneuve said publicly that she was enjoying making the film. Other than remarking that shooting some of the brothel scenes could be "difficult," she said at the time that she was "in awe" of Luis Buñuel and called him "wonderful to work with; kind, understanding, very sweet, very human."
For the striking opening sequence in which the audience first gets a glimpse into Séverine's masochistic fantasies, Luis Buñuel originally wanted to use an entirely different location. He recalled, "...my only regret about Belle de Jour was that the proprietor of the famous Train Bleu at the Gare de Lyon refused to allow me to shoot the opening scene on the premises. It's a spectacular restaurant on the second floor of the railroad station, designed around 1900 by a group of painters, sculptors, and decorators who created a kind of opera-house décor devoted to trains and the countries they can take us to."
41 years later Portuguese director Manoel de Oliveira released Belle toujours (2006) which is an (unofficial) imagining of what could have happened to the lead characters of this film many years later.