Disgusted by the smarminess of his 1963 vehicle Under the Yum Yum Tree, Jack Lemmon vowed that his next effort would be a wholesome family picture. Good Neighbor Sam is suitable for all ages, to be sure, but that doesn't stop producer-writer-director David Swift from injecting plenty of double-entendre dialogue and harmlessly risque situations. Lemmon plays ad executive Sam Bissell, happily married to all-American blonde Minerva (Dorothy Provine). Anxious to land the Nurdlinger's milk account, Sam is carefully scrutinized by the prudish Simon Nurdlinger (Edward G. Robinson), a staunch advocate of old-fashioned family values.
Meanwhile, Minerva welcomes her old school friend, sexy Janet Langerlof (Romy Schneider) into her home. Janet is in line to inherit a fortune, but only if she's married. Unfortunately, Janet is currently separated from her insanely jealous spouse Howard Ebbets (Michael Connors), so big-hearted Minerva volunteers Sam to pose as Janet's husband. The ensuing comic complications come to a head when Nurdlinger elects Sam and Janet as the nation's ideal "married" couple, and posts their pictures on billboards all over town! Some of the smaller pleasures in this film are provided by Louis Nye as a high-tech private eye, Joyce Jameson as a squeaky-voiced call girl, Robert Q. Lewis as Sam's lascivious neighbor, and an uncredited Gil Lamb as a genial wino. An amusing running gag involved the Hertz "man in the driver's seat" commercials of the 1960s has sometimes been cut from TV prints of Good Neighbor Sam.