Due to the Hays Code, much of the film had to be watered down from El hombre y el monstruo (1931). The character of Ivy Peterson had to be changed from a prostitute to a barmaid.
The film was a notorious critical failure when released, although it eventually made a profit of $2 million around the world. Spencer Tracy later said it was by far the least favorite of the films he had starred in, and that his performance was "awful". The New York Times famously described it as "not so much evil incarnate as ham rampant ... more ludicrous than dreadful."
One night Spencer Tracy turned up at Clark Gable and Carole Lombard's second wedding anniversary party wearing his make up as Mr. Hyde.
Despite having not yet met his famous future co-star, Spencer Tracy wanted the characters of Ivy and Beatrix to be played by the same actress, Katharine Hepburn, to reinforce the theme of the good and bad qualities in every individual.
When author W. Somerset Maugham visited the set during the filming, he supposedly watched a bit of Spencer Tracy's performance and asked sardonically, "Which one is he now, Jekyll or Hyde?"