When Jack Benny's father went to see this movie, he was outraged at the sight of his son in a Nazi uniform in the first scene and even stormed out of the theater. Jack convinced his father that it was satire, and he agreed to sit through all of it.
When war breaks out in Poland there's a scene where grave stones are destroyed by the bombing by the German forces. One of the grave stone that is shattered has the name "Benjamin Kubelsky" which is Jack Benny's birth name.
Miriam Hopkins was the original choice for Maria Tura. According to Ben Mankiewicz on TCM, she turned the role down when she realized Jack Benny had all the laughs and her part would largely be his straight man. Lombard saw the overall quality of the material and took the part.
According to the book 'The United Artists Story' by Ronald Bergan, "Unfortunately, at its release, Pearl Harbor had been attacked, Germany was sweeping across Europe, and the film's star, Carole Lombard, was killed in a plane crash while on a war-bond selling tour. Therefore, neither critics nor public were in the mood to laugh, finding the picture tasteless and callous. Over the years, however, it recovered its production costs and became a classic."
Maria's scheduled meeting with Col. "Concentration Camp" Ehrhardt is shown highlighted in the Colonel's appointment book. Other appointments are also shown, unhighlighted. One of the appointments is with "Schindler" - presumably Oskar Schindler of Schindler's List (1993) fame, likely to discuss Schindler's use of concentration camp inmates in his factory.
The biggest problem early in the shoot was Jack Benny's insecurity about acting the central role in such an important production by a major filmmaker. He seemed dumbfounded that Ernst Lubitsch had not only cast him but was building the film around him. Finally Lubitsch set him straight: "You think you are a comedian. You are not even a clown. You are fooling the public for 30 years. You are fooling even yourself. A clown - he is a performer what is doing funny things. A comedian - he is a performer what is saying funny things. But you, Jack, you are an actor, you are an actor playing the part of a comedian and this you are doing very well. But do not worry, I keep your secret to myself."
According to Jack Benny's daughter, Joan, he loved his director and "would have done anything for Lubitsch." But even after the encouraging words, he remained nervous about his role. According to Robert Stack, "Jack was an innocent. He'd never done a movie that worked. He'd always ask me, 'Is this funny?' and I'd say, 'Jesus, don't ask me.' 'But you're an actor,' he'd say. Basically he was scared to death." Benny seemed to appreciate having Lubitsch act out his scenes for him, saying later that he was "about the only director who ever really directed me... The trouble was that I knew lots about radio comedy, a little about stage comedy and nothing about movies."
One of Ernst Lubitsch's techniques to protect his star was having Jack Benny do multiple takes of many of his crucial scenes. Robert Stack recalled that "Specifically, the scene where Jack comes home and finds me in his bed asleep and does a series of double takes, he made Jack do at least 30 takes." Still, Lubitsch respected Benny's opinion and would redo a scene if Benny himself, after looking at the rushes, thought it could be better.
The atmosphere on the set was light and congenial. Candid photographs shot during breaks in filming invariably show everyone in the cast and crew laughing hilariously. Carole Lombard would drive to the set from her ranch in the San Fernando Valley even on her off days, just to watch Ernst Lubitsch work with the other actors. Although Lubitsch treated his script with total respect, he often found moments of inspiration on the spot. One example: In the scene at the end where the Nazi Col. Ehrhardt goes behind a closed door to commit suicide, the script indicates only that a shot rings out. But Lubitsch added a topper where Ehrhardt - who has established a habit of screaming out for his assistant's help at every turn - is then heard once again yelling for "Schultz".
In early January 1942, as Ernst Lubitsch was editing the film, United Artists informed him that To Be or Not to Be, with its Shakespearean reference, seemed "too highbrow" a title and that thought should be given to changing it. Impishly, because he had anticipated censorship problems with the script, Lubitsch suggested The Censor Forbids as an alternate title. Suspiciously, both Carole Lombard and Jack Benny fired off almost identical cables describing the new title as "suggestive" and allowing that, as participants and investors in the film, they objected strongly to the change. Benny even said he would refuse to promote the movie on his radio show if such a title were used. Lubitsch then informed UA that, in view of these objections, he had no choice but to withdraw the alternate title. UA, clearly overmatched, said no more about it.
Ernst Lubitsch held the film in high regard as one of his best pieces of work. In a letter to a reviewer for the Philadelphia Enquirer who had panned the movie, he wrote, "What I have satirized in this picture are the Nazis and their ridiculous ideology. I have also satirized the attitude of actors who always remain actors regardless how dangerous the situation might be, which I believe is a true observation. It can be argued if the tragedy of Poland realistically portrayed in To Be or Not to Be can be merged with satire. I believe it can be and so do the audience which I observed during a screening of To Be or Not to Be; but this is a matter of debate and everyone is entitled to his point of view..."
Ernst Lubitsch had never considered anyone other than Jack Benny for the lead role in the film. He had even written the character with Benny in mind. Benny, thrilled that a director of Lubitsch's caliber had been thinking of him while writing it, accepted the role immediately