The script for La Otra was owned by Warner Bros. and is the same script as the 1964 version, Dead Ringer (1963), starring Bette Davis. Warners chose to pass on making it as a film in the 1940's because it bore too close of a resemblance to the film Davis had just made, A Stolen Life (1946).
The 96-page script was originally titled "The Other Woman" by José Revueltas, Jack Wagner and Roberto Gavaldón from a story by Rian James. The Paul Kohler Agency represented the screenwriters.