William Friedkin's powerful adaptation of William Peter Blatty's bestselling novel was submitted to the BBFC at the beginning of 1974. The film tells the story of a young girl who is possessed by a demon.

The film had already courted controversy in the US where it had supposedly provoked fainting, vomiting and heart attacks in cinemas.

Nonetheless, in spite of its more sensationalist moments, the BBFC considered that The Exorcist was suitable for an X certificate to be issued without cuts. As the BBFC's Secretary, Stephen Murphy, said at the time, "It is a powerful horror movie. Some people may dislike it, but that is not a sufficient reason for refusing certification''.

Given the recent controversy over films such as A Clockwork Orange, Trash, Straw Dogs and Last Tango in Paris, it was perhaps unsurprising that the film's UK release provoked a certain degree of outrage, particularly amongst pressure groups such as the Festival of Light. However, the film was a huge popular success at the box office and the public as a whole did not seem overly concerned. Despite this, a handful of local authorities bowed to the demands of pressure groups and banned the film in their areas, which only added to the reputation of the film.

In 1979 the BBFC asked to look at the film again to see whether some of the scenes involving the young actress, Linda Blair, might be vulnerable under the new Protection of Children Act 1978, which made the distribution of 'indecent' images of children illegal. After careful consideration it was decided that the scenes in question were constructed specifically to avoid any such images, and the film was allowed to continue its ongoing - and still popular - late-night screenings.

In 1981, the film was released on video by Warner Home Video, as one of their first UK releases. At the time, there was no requirement that videos should be classified by the BBFC so the video was simply released on the strength of its existing X certificate. Contrary to popular opinion, the video version was never included on the Director of Public Prosecution's list of 'video nasties' and was never prosecuted for obscenity - testament perhaps to the popularity of the film and the high regard in which it was held.

After the Video Recordings Act (VRA) was introduced in 1984 it became necessary for The Exorcist to obtain a certificate for video release from the BBFC. Because of the huge number of titles already on the shelves, the BBFC was given four years in which to work through those titles that had already been released, determining whether they should be allowed to remain on the shelves (and, if so, with what classification) or whether they must be withdrawn from sale.

As the 1988 deadline for making a decision on The Exorcist approached, the BBFC continued to debate whether the film was suitable, within the meaning of the VRA, for 'viewing in the home'. Of particular concern was the fact that the protaganist of the film was aged 12 and the film might therefore have significant appeal to underaged viewers. At the cinema it had been relatively easy to ensure that young children would be excluded but video was a different matter. Adding to the BBFC's difficulties were the reports of incidents of hysteria involving young women, which had led to concerns that the film might cause severe emotional problems, particularly among those who believed in the reality of demonic possession.

It was with this concern in mind that the BBFC in the 1980s and early 1990s concluded that a video classification - even with an 18 rating (which could not entirely exclude the possibility of the work being seen by younger and susceptible viewers) - was inappropriate.

Therefore, at the beginning of 1988, the video was removed from the shelves (after nearly seven years of free availability) and was to remain unavailable for 11 years. Despite the prohibition on the video version, the film continued to play occasionally in cinemas, its existing X certificate being replaced by a new 18 certificate - for cinema release only - in 1991.

In 1998, the distributors decided to celebrate the film's 25th Anniversary by relaunching the film in UK cinemas. The BBFC watched this re-release with interest, as it was widely expected that a fresh attempt to obtain a certificate for video (and now DVD) release would inevitably follow. The cinema re-release was notable in that it was not accompanied by any of the hysteria or audience disturbance which supposedly occurred in the mid-1970s.

When the film was formally resubmitted for video/DVD release at the end of 1998, the BBFC concluded that The Exorcist, while still a powerful and compelling work, no longer had the same impact as it did 25 years ago. Film technique and special effects had moved on a long way since then, and audiences - including (or especially) teenagers brought up on a range of modern multi- media output - were less likely to be affected. Correspondingly, the potential of The Exorcist to disturb a small, impressionable minority seemed to have been significantly diminished.

The BBFC also considered the likely effects of the film's reputation. Whilst unable to discount the possibility that, however restrictive its classification, under-age persons may seek ways to view it , both the name and the nature of the film were familiar to most people. It was considered that its reputation should prompt many parents and guardians to be more alert to that possibility than would normally be the case.

Therefore the BBFC agreed that The Exorcist could finally be classified 18 uncut for video/DVD release, at a level which minimised the likelihood of the work being viewed by young and impressionable persons.

A DVD version was submitted to the BBFC in 2010 with very minor changes to the end credits These did not affect the content, and so the same classification of 18 was again given, with BBFCinsight added of 'Contains very strong language, strong threat and supernatural horror'.