Although the name pendants, monogrammed dressing gowns and brooches are swapped for plot purposes, Terry is consistently left-handed and the only smoker.
Dr. Scott Eliott (Lew Ayres), when confronting Terry at the end, explains to her that between sisters there can be bitter rivalry. In real life, Olivia de Havilland had such a rivalry with her sister, Joan Fontaine.
First film distributed by the new joint venture Universal Pictures-International Pictures.
Lt. Stevenson warns the sisters about a Rube Goldberg defense. This refers to the Pulitzer-prize-winning author and cartoonist Rube Goldberg, famous for his diagrams of complicated machines that perform simple tasks. He inspired Rube Goldberg Machine Contests that feature heavily on YouTube.
One of thirty feature films produced between 1946 and 1948 whose financial failure resulted in their ownership being taken over by Bank of America for non-payment of loans, and subsequently sold to Mundus Television in 1954 for television broadcast at a reported total of $45 million.