Based on David Benedictus' 1963 novel of the same name, it stars Elizabeth Hartman, Peter Kastner, Geraldine Page, her spouse Rip Torn, Karen Black, and Julie Harris.

His unhappy mother acquiesces to her husband's decision and arranges for Bernard to live in a rooming house run by nosy, prudish Miss Nora Thing.

Miss Thing inherited the building on the condition that her late brother's aggressive pet rooster be allowed to occupy the fifth floor, which Bernard must pass to get to his room.

Bernard's worldly co-worker Raef Del Grado encourages him to date Amy because she's a "sure thing" (a girl that will sleep with him) and discourages him from trying to pursue Barbara.

Amy tries to win him back by offering to spend the night with him and Bernard accepts, though he's thinking of Barbara the entire time.

When they try to go to Bernard's room, the rooster attacks Amy, causing a commotion during which Miss Thing falls down the stairs and breaks her arm.

Miss Thing and her new boyfriend, police officer Francis Graf, who lives in her boarding house, also arrive to confront Bernard's father about what happened in the vault.

Barbara is featured in the newspaper for stopping a rare book thief and saving the Gutenberg Bible for the City of New York.

The idea for the film came from Tony Bill, who was a fan of David Benedictus' novel and hoped to play Bernard, but was cast instead as the duplicitous co-worker Raef Del Grado.

Coppola and his crew concealed three cameras in carts and shopping bags and filmed the ensuing mayhem with natural light.

[7] In the scene where Bernard roller skates through Manhattan streets after receiving Barbara's letter, the facade of the landmark original Pennsylvania Station (then in the process of being demolished) is briefly visible, with Madison Square Garden being constructed behind it.

[4] The film scenes projected on the walls of the discotheque where Bernard and Amy go on a date are from Coppola's first directorial effort Dementia 13 (1963).

[3] You're a Big Boy Now was released a year before Mike Nichols' The Graduate, which deals with similar themes of a young man getting involved with a predatory female and attempting to escape the societal conventions of his parents' generation.

[10][11] Geraldine Page was nominated for the Academy Award for Best Supporting Actress category for her performance as Bernard's mother Margery Chanticleer, but did not win.