In order to help his friend Edie Adams out financially, after the sudden death of her husband ('Ernie Kovacs') left her debt-ridden, star/co-producer Jack Lemmon not only insisted upon hiring her for this film, but further insisted that her part be expanded considerably from the original stage play to give her more work.

The red sports car driven by Hogan was a 1962 Cougar I concept car. It was introduced at the 1962 Chicago Auto Show.

Adapted from a Broadway play by Lawrence Roman. Dean Jones was in the original Broadway cast, and Gig Young played Hogan. The stage production opened Nov 16, 1960 at Henry Miller's Theatre in New York and ran for 173 performances.

According to movie magazines of the day, Natalie Wood, Ann-Margret and Sandra Dee reportedly vied for the role played by Carol Lynley.

"Yum Yum" was playing at first-run theaters across America the day President Kennedy was assassinated.

Jim Hutton was mentioned for the Dean Jones role.

Gig Young originally announced to recreate his stage role on film but part went to Jack Lemmon instead.