The liquor industry was so afraid of the public response to The Lost Weekend that they supposedly offered Paramount Pictures $5 million dollars to destroy the film ahead of release. (Source.)

Ray Milland went on a very strict diet in order to lose enough weight to look like an alcoholic. He even tried to get drunk so he could get inside Don's head, but being a lightweight, he just ended up puking. (Source.)

The story goes that Billy Wilder picked up a copy of the novel The Lost Weekend before taking a cross-country train trip, and by the time he got to his destination, he knew that he wanted to adapt it to film. (Source.)

While working on the film, director Billy Wilder (who was married) sparked an affair with Doris Dowling, who played Gloria. Scandalous! (Source.)