The film's world premiere was near the end of the Cannes Film Festival 2009 because the film was not finished at this time. Around 50 graphic artists were working on finishing the film. The running time of this festival cut was 163 minutes. Because of the tight schedule, the film was screened without opening or closing credits. The film started with "Enter" and ended with "The Void."
Gaspar Noé planned Enter the Void (2009) over a period of 15 years - before his short film Carne (1991). He was around 23 years old, when he saw Robert Montgomery's Lady in the Lake (1947) on drugs. The film is shot in subjective camera, entirely from the point of view of the main character. For Enter the Void, Noé uses a subjective camera in the same manner. The main character Oscar is seen just once while the character is alive (in a mirror.)
The ambient score of the film was assembled from existing music and sound sources collected by Thomas Bangalter from Daft Punk, whom Noé really wanted to compose the film's score but couldn't because Disney already tapped Daft Punk for the soundtrack of TRON: Legacy (2010)' at the time.
After the Cannes Film Festival the post-production continued. Sensory, visual and auditory elements were accentuated. Gaspar Noé edited out 4 minutes of the film and added opening credits (about 2 minutes).
During the Cannes Film Festival 2008, the distributor Wild Bunch presented the first teaser-trailers of "Enter The Void", one year before the film was shown in competition 2009 at this Festival. The press book contains, beside the usual synopsis a note of Gaspar Noé. This director's note begins with a quote from Steven Spielberg: "Making a film is difficult, but making a great film is an almost impossible task."
4 months after the world premiere in Cannes - the film, still not completely finished, was presented a second time at the Toronto Film Festival in September 2009. Close after this festival, the film was shown at several international film festivals - in Cataluña, London (both in October 2009), Stockholm (November 2009) and Tallinn (December 2009)
The exact running time at the BFI London Film Festival was 161 minutes. When the film was theatrical released in France on 5th of May 2010, the running time was approximately 154 minutes (official press book). It's clear that Gaspar Noé made some further minor changes: for example the opening credits at BFI London Film Festival were slightly different in its typography and the music from "LFO-Freak" wasn't used there either.