This was released the year i was born and my Mam loves to tell me she almost went into labour whilst watching it. It was obviously deemed scary in the 70's!
The story of a young girl 'possessed' by the devil himself is supposedly based on the true story of a young American boy in the late 1800's. The acting is mediocre at best (although Max Von Sydow is excellent as usual) and I think the whole film relies on 'shock' value rather than a decent story.
Personally I think the most disturbing thing about this is the fact that a young child was allowed to act out some very explicit scenes with the blessing of her Mother. Thats the scary part!