James Stewart later declared in an interview that Josephine Hull had the most difficult role in the film, since she had to believe and not believe in the invisible rabbit ... at the same time.
In 1990, James Stewart recorded an introduction to the VHS release of the film, which turned out to be one of the biggest-selling videos of the year.
At the suggestion of James Stewart, the director changed many shots to make them wider so that "Harvey" would be in the frame.
As a joke, the cast and crew would often set a chair for the title character at lunch and order him something to eat.