The Big Sleep is known for its convoluted plot. During filming, allegedly neither the director nor the screenwriters knew whether chauffeur Owen Taylor was murdered or had killed himself. They sent a cable to Chandler, who told a friend in a later letter: "They sent me a wire ... asking me, and dammit I didn't know either".
After its completion, Warner Bros. did not release The Big Sleep until they had turned out a backlog of war-related films. Because the war was ending, the studio feared the public might lose interest in the films, while The Big Sleep's subject was not time-sensitive. Attentive observers will note indications of the film's wartime production, such as ration stamps (including references to dead bodies as "red points," referring to wartime meat rationing), period dialogue, pictures of President Franklin D. Roosevelt, and a woman taxi driver who says to Bogart: "I'm your girl."
The "Bogie and Bacall" phenomenon, which had begun with To Have and Have Not and their marriage, was in full swing by the end of the war. Bacall's agent, Charles K. Feldman, asked that portions of the film be reshot to capitalize on their chemistry and counteract the negative press Bacall had received for her 1945 performance in Confidential Agent. Producer Jack Warner agreed, and new scenes, such as the sexually suggestive racehorse dialogue, were added.
The reshot ending featured Peggy Knudsen as "Mona Mars" because Pat Clark, the originally cast actress, was unavailable. Because of the two versions created by the reshooting, there is a substantial difference in content of some twenty minutes between them, although the difference in running time is two minutes. The reshot, revised The Big Sleep was released on 23 August 1946.
The cinematic release of The Big Sleep is regarded as more successful than the pre-release version, although some complain it is confusing and difficult to follow. This may be due in part to the omission of a long conversation between Marlowe and the Los Angeles District Attorney where facts of the case, thus far, are laid out. Yet movie-star aficionados prefer it to the film noir version because they consider the Bogart-Bacall appearances more important than a well-told story.