The Trouble with Angels is a 1966 American comedy film about the adventures of two girls in an all-girls Catholic school run by nuns.

A sequel, Where Angels Go, Trouble Follows, starring Stella Stevens, was released in 1968, with Russell, Barnes, Wickes and Dolores Sutton all reprising their roles as nuns.

The movie is set at St. Francis Academy, a fictional all-girls Catholic boarding school in Pennsylvania operated by an order of nuns.

The episodic story line follows the young women through their sophomore, junior and senior high-school years as they pull pranks on the sisters and repeatedly get into trouble.

As time passes, Mary is touched by the sisters' dedication, devotion, kindness, love, and generosity; she gradually begins to understand that their lives are of fulfillment, not deprivation.

Mary experiences "the call" senior year and, after graduation, decides to remain at St. Francis to begin her novitiate in the order.

[5] In June 1962, the film rights were purchased by Ken Donnellon and Jacqueline Babbin who knew Trahey in advertising.

The exterior track-side train/depot scenes (at the opening and closing of the movie) were shot at the former Atchison, Topeka, and Santa Fe Railway depot in Monrovia, California featuring ALCO PA's.

The world premiere and a reception were held at St. Louis's Fox Theatre with ticket proceeds going to the school's building fund.

The film marked a departure for Mills, who was attempting to emerge from her juvenile leads in Walt Disney-produced teen comedies as a comedic actress.

The Trouble with Angels enjoyed good reviews, although Variety was critical: "An appealing story idea—hip Mother Superior nun who outfoxes and matures two rebellious students in a Catholic girls' school—has lost impact via repetitious plotting and pacing, plus routine direction....Graduation finds Mills in character switcheroo to which Catholic audiences will long since be alerted".

"[23] However she opted not to reprise her role as the progressive protagonist in the sequel and was replaced by Stella Stevens, who played Sister George, a new foil to Rosalind Russell's Mother Superior.