[2] The film's plot—which involves some couples who switch partners on a summer night—has been adapted many times, particularly as the theatrical musical A Little Night Music by Stephen Sondheim, Hugh Wheeler and Harold Prince, which opened on Broadway in 1973, and as Woody Allen's film A Midsummer Night's Sex Comedy (1982).

Henrik is distracting himself from his urges by attempting an inconclusive affair with Egerman's lusty young servant, Petra.

Between his two marriages, Fredrik had an affair with a prominent stage actress, the beautiful Desiree Armfeldt, but she broke off the relationship.

Henrik and Anne, unexpectedly finding themselves alone together in a bedroom, consummate their relationship and elope with the assistance of Petra and her new lover Frid, another servant.

Learning his wife is with Egerman, the Count bursts in and challenges Fredrik to a game of Russian roulette.

Smiles of a Summer Night was filmed on location at Jordberga Castle in Scania and at Svensk Filmindustri's Filmstaden in Råsunda, Stockholm, beginning on 28 June 1955 and completing on 29 August, except for two additional days in November 1955.

[3] The film premiered at the Red Mill (Swedish: Röda Kvarn) cinema in Stockholm on 26 December 1955.

[3] Smiles of a Summer Night opened to highly positive reviews[4] and is viewed favorably today.