Based on a 1971 novel by William Peter Blatty[?] and adapted by him the film was a huge international hit, the most successful horror film ever. It was nominated for ten Academy Awards (won two) and also won four Golden Globes. For its time the film had a number of graphic and disturbing effects.
The plot is supposedly based on a true story. A young girl living in Georgetown, Washington becomes possessed by Pazuzu and undergoes a series of physical changes, as well as gaining certain malevolent powers. Chris MacNeil, Regan's mother, failed by medicine, turns to religion -- the girl is examined by a priest, Father Damien Karras, who is convinced of the diabolical nature of the case and turns to a second priest, Father Lankester Merrin, to perform an exorcism.
There were two sequels and innumerable rip-offs. A number of tales have also arisen from the making of the film, regarding accidents and deaths amongst the cast and crew.
wikipedia.org dumped 2003-03-17 with terodump