In 1973, a new version of "A Clockwork Orange" was released to theaters with an MPAA rating of "R", replacing the previous "X". The new version contained approximately 31 seconds of replacement, less lascivious footage for two scenes: the high speed (2 fps) orgy in Alex's bedroom, and the Ludovico rape scene. The bedroom scene was made more comical by having one of the girls fall off the bed and Alex joins her down there. The Ludovico rape scene was altered in that the scenes with the first two droogs was from the side and waist-up, so it is less explicit. The third droog was removed completely and replaced with a close-up of one of the doctor's face as they are watching Alex's treatment.
In 1986, the full uncensored "X" rated version of the film was released on home video, and later on DVD, despite the fact that the video/DVD sleeve bears the "R" rating (which leads people to believe it's the censored version). The MPAA never re-rated the uncut version as an "R", but the uncensored version does bear the "R" certification on the DVD/video box.
The Japanese version has every single scene of nudity blurred out.
The home video version originally released in Brazil lacks the religious service in prison. This scene is only available in the recently released Stanley Kubrick Collection DVD/VHS versions.
In the 1971 X version, when Alex is smashed with the milk bottle, it is in slow-motion. In the edited R version, it is at normal speed.