Sir Christopher Lee said that he considers this to be one of his greatest ever roles.
The "evil eye" rowing boat, which takes Sergeant Howie (Edward Woodward) to and from his plane, was not constructed for this movie. It belonged to a resident of Plockton. Upon seeing it, the producers decided it would suit the movie. The boat survived until 2004 when it was destroyed in a storm.
Many years after making the film Edward Woodward re-visited some of the locations and claimed that he found the makeshift cross (that Howie makes out of some pieces of wood) still intact where it was left in the original scene.
Director Robin Hardy explained the meaning of the scene with the woman with an egg in her hand nursing a baby while sitting in a graveyard to Alan Cumming in Scotland on Screen (2009). According to Hardy, it is a fertility ritual and she was hoping for another baby.
According to director Robin Hardy, while this movie was largely filmed in Scotland, the aerial shots from the plane arriving were filmed in South Africa, because they didn't have the budget to glue blossom to that many trees.
Anthony Shaffer: The screenwriter was present during the filming of the final scenes and is said to be amongst the villagers.