The college scenes were shot at Connecticut College for Women in New London Connecticut. The book was somewhat autobiographical about Mary McCarthy and her friends who went to Vassar College. In 1969 both colleges went coed and began to admit men.
In 1933, Dottie Renfrew (Joan Hackett) tells Dick Brown (Richard Mulligan) that she is the oldest member of the group at 23. In reality, Hackett was the oldest of the eight actresses to play one of the members of the titular group, having been born in 1934.
Longstanding rumor has suggested that producer Charles Feldman, having already bought the film rights to Mary McCarthy's novel in advance of publication, made sure it would be a best-seller by sending employees to bookstores all over America to buy up numerous copies of it. The prestige accruing to the book allowed him and Sidney Lumet to make the film with unknown actors and without too much interference.
The making of this film was the subject of a notorious long article written by the critic Pauline Kael, who was present throughout the shooting and who attacked almost every aspect of the film, accusing the leading actresses of being pretentious and snobbish, the director of being incompetent and a fool and the screenplay of being a travesty of what Mary McCarthy had written about. At no point did she address the obvious question arising from her remarks (how good was the finished film?), perhaps because she (years later) conceded that it had turned out quite well and that she had enjoyed it. The essay is included in her collection, "Kiss Kiss Bang Bang".
Sidney Lumet accepted to directed the film purely on the basis of Sidney Buchman's screenplay, which he praised highly and to which (so he claimed) he made no alterations. He did not read Mary McCarthy's novel until later and was dismissive of it, saying the screenplay had improved upon it.
The trivia item below may give away important plot points.
Although her death was an accident, the authorities erroneously believe that Kay Strong Latham (Joanna Pettet) killed herself by jumping out the window of her apartment. On June 10, 1987, Elizabeth Hartman (Priss Hartshorn Crockett) committed suicide in this fashion.