The interior of The American Bookshop is the set of the River City Library from Warner Bros. The Music Man (1962).
Donahue and Pleshette were later married in real life, if for only nine months.
The book that Prudence is disciplined for giving to her student is "Lovers Must Learn" by Irving Fineman, the novel this film is based upon. This was also the title used during filming.
The establishing shot of Briarcroft College For Women at the beginning of the film is actually an outtake from the film "Parrish" made a year earlier. It is a shot of Paige Raike returning home on her bicycle after having spoken with Parrish at the tobacco field.