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."
Robert Mitchum was very eager for the part of the preacher. When he auditioned, a moment that particularly impressed Charles Laughton was when he described the character as "a diabolical shit" Mitchum promptly answered, "Present!"