When Teresa meets Tony in the bar, she is reading "The Godfather", just as she does in the original novel. He comments that he has seen the movie. Diane Keaton (Teresa) plays the part of Kay in The Godfather (1972).
Mary Ellen Mark, a documentary photographer, was asked to go to bars and take pictures of the bars to play during the opening credits. The director rejected the pictures because they were "too realistic."
One of two feature films that actress Diane Keaton starred in in 1977. The other film was Annie Hall (1977) for which Keaton won the Best Actress Academy Award. Keaton was not Oscar nominated for her performance in Looking for Mr. Goodbar (1977). The movie did receive two Oscar noms though, for Best Actress in a Supporting Role (Tuesday Weld) and Best Cinematography (William A. Fraker) but failed to win either.
Director Richard Brooks interviewed around 600 women who had read the film's source novel. This was so as to connect with the film's "magical key" which was the popularity of the book which had become a best seller. Brooks used the meetings for insight and feedback in preparation to make the picture.