Originally director Alan J. Pakula did not want Burt Reynolds for the Phil Potter part, feeling he was not the right type: he wanted a New York-trained actor along the lines of Al Pacino or Dustin Hoffman. But Reynolds lobbied hard for the role, and Pakula finally let him audition. After two auditions, Reynolds had the role, and Pakula subsequently has praised his work in the film.
According to the book 'Rating The Movie Stars' by Joel Hirschhorn, Burt Reynolds " . . . was reportedly angry when co-stars Jill Clayburgh and Candice Bergen received Oscar nominations for Starting Over (1979) and he was ignored."
One of the locations was an actual apartment building in New York City. Tenants were upset because they were forbidden from entering or leaving their apartments while scenes were shot in the hallway.
The shower of Valium pills was based on an actual incident that happened to Burt Reynolds. Later, the film's co-star Jill Clayburgh actually starred in a film about Valium addiction called I'm Dancing as Fast as I Can (1982) which was based on the book by Barbara Gordon.
Due to delays in filming Bernardo Bertolucci's Luna (1979), actress Jill Clayburgh missed attending a number of awards ceremonies for which she had been nominated for An Unmarried Woman (1978) whilst dubbing sessions for Luna (1979) had to be postponed until Clayburgh had finished work on Starting Over (1979).