Originally Liebeswalzer, this German operetta was the third talkie vehicle for the effervescent Lillian Harvey. The plot is a typical Graustarkian affair, with Princess Eva (Harvey) preparing to marry a duke whom she's never met. Getting cold feet, the duke ducks the wedding, persuading a handsome young commoner named Bobby (Willy Fritsch) to take his place. The wedding goes on as planned, with Eva never suspecting that her new hubby is a ringer. Eventually, the false duke confesses everything, leading to all sorts of intrigue before a happy ending can be realized. Love Waltz was simultaneously filmed in an English-language version, which posed no problem for the British-born Harvey but caused a few uncomfortable moments for her Teutonic co-stars (eventually, Willy Fritsch was replaced by John Batton, who'd played a bit role in the German version).

Marcia Saville, thought to be a hopeless flirt by her sweetheart, Martin Kent, shows him that she prefers Tom Smith, a man from the underworld, because Tom is more authoritative. Tom is induced to enter a scheme to rob Marcia's father in a crooked deal instigated by Simon Downs. Downs plans to have Tom marry Marcia and divide the spoils, as she is to receive a sum of money when she marries. Tom is too smart for them and refuses to get involved. Meantime, Kent proves his strength of character, and Marcia is won over. Downs is exposed to her father and discharged.