When it was first released, the film was so horrifying that people actually walked out on sneak previews for it
Marilyn Burns, whose character was chased by Leatherface through the undergrowth actually cut herself on the branches quite badly, so a lot of the blood on her body and clothes is real.
DVD Easter Eggs: (Hidden So You Don't See Anything You Don't Want To See)
Edition: Pioneer Video
Description: Alternate takes of decomposed body
Go to a deleted scene where they have some flashing shots of decomposed skeletons cut from the flashing light dead body scene at beginning of the movie. Play the deleted scene until the end.(Do not press stop or go back to maim menu). After deleted scene is finished it has part 2 of the deleted takes also showing all the explainations highlight play and enter to see the alternate takes of the decomposed graveyard body.