Trivia

When this movie was produced, MGM attempted to have all prints of the previous version, Gaslight (1940), destroyed. These efforts were ultimately unsuccessful, though the movie was rarely seen for the next few decades.

Director George Cukor suggested that Ingrid Bergman study the patients at a mental hospital to learn about nervous breakdowns. She did, focusing on one woman in particular, whose habits and physical quirks became part of the character.

Charles Boyer's wife, Pat Paterson, was pregnant with what would be the couple's only child. Boyer and Paterson had been trying to have a baby for many years, and Boyer was exceptionally nervous while making this movie. He rushed between takes to call and check on his wife's health as the expected birth date grew nearer. The baby was expected to come after Boyer had finished working on this movie, but he arrived early while Boyer was on set. Boyer broke down in tears when he was notified, and he informed the rest of the cast and crew of his son's birth. Production was halted for the day and the cast and crew opened up bottles of champagne to celebrate the birth.

The first time Ingrid Bergman encountered Charles Boyer was the day they shot the scene where they meet at a train station and kiss passionately. Boyer was the same height as Bergman, and in order for him to seem taller, he had to stand on a box, which she kept inadvertently kicking as she ran into the scene. Boyer also wore shoes and boots with two-inch heels throughout the movie.

The scene in which Dame Angela Lansbury lights a cigarette in contradiction to Ingrid Bergman's wishes had to be postponed until toward the end of production. Lansbury was only seventeen when filming began, and because she was a minor, she had to be monitored by a social worker who refused to allow Lansbury to smoke, and the scene had to be postponed until her eighteenth birthday. When Lansbury walked on set on her birthday, Bergman and the crew had organized a party for her, and the cigarette scene was shot immediately after they celebrated her birthday.