Maureen Stapleton turned down role of Frank Sinatra's mother. The part went to Molly Picon instead. According to one fan magazine, Stapleton (who'd just played Dick Van Dyke's mother in Bye Bye Birdie (1963), even though she was just a few months older than him) passed on the role because Sinatra was roughly eight years older than her and she didn't want to make a career playing mothers to her contemporaries.
Lee J. Cobb, who played Frank Sinatra's father, was actually only four years older than Sinatra. Tony Bill, who played Sinatra's younger brother, was 25 years younger than Sinatra. Molly Picon, who played Cobb's wife, was 13 years older than Cobb.
In one scene, when Frank Sinatra spins a vinyl LP, two turntables are seen showing a matching pair of albums on the Reprise label. Reprise was the label for which Sinatra recorded and of which he was part owner. Each record was labeled with a print of a smiley Sinatra face.
First Neil Simon film to get Oscar nominated. The Academy Award nom was for Best Color Art Direction. Quite a number of Simon written films would get nominated for Academy Awards throughout his career.