The sequence with Powell riding a horse in the distance was actually a dwarf on a pony. It was filmed in false perspective.
Later on in life, Robert Mitchum, who was usually indifferent to such matters, said that Charles Laughton was his favorite director and indicated that this was his favorite of the movies in which he had acted.
Dutch-born American serial killer Harry Powers (né Herman Drenth) was the inspiration for the Preacher.
At their initial meeting, Lillian Gish asked Charles Laughton why he wanted her for the part and he replied, "When I first went to the movies, they sat in their seats straight and leaned forward. Now they slump down, with their heads back, and eat candy and popcorn. I want them to sit up straight again."
Charles Laughton reportedly worked well with the boy playing John, but did not get along with the girl playing Pearl and shouted at her on occasion. As Laughton had the camera continue to roll after the scenes were finished, the camera often caught her reacting to him. Some of these out-takes were used in the final editing process as reaction shots to the Preacher's character.