During World War II, she was a regular volunteer at the Hollywood Canteen, where she danced with servicemen and signed hundreds of autographs. She was featured with Robert Hutton, among many others, in the Warner Bros. film "Hollywood Canteen" (1944). Like most of the other Hollywood stars appearing in the film, she played herself, but the fictionalized plot had her falling in love with a soldier (played by Hutton) frequenting the canteen. Her sister, actress Betty Brodel, briefly played herself in the film as well. In 1946, an exhibitors' poll conducted by "Motion Picture Herald" voted Leslie the most promising star of tomorrow.