Playwright Terrence McNally originally wrote the role of Frankie for Kathy Bates. Johnny was played by Kenneth Welsh in the 1987 Off-Broadway production of "Frankie and Johnny in the Clair de Lune" that starred Bates.
Kathy Bates, who had originated the role of Frankie on stage, was passed over in favor of Michelle Pfeiffer - a fate that often seemed to befall her stage characters when transferred to the screen, which delayed her eventual success on film. Ironically, in this case, it was Marshall's former brother-in-law, Rob Reiner, who gave Bates her big-screen break in Misery.
The casting of Michelle Pfeiffer was met with some negativity as many felt the actress was too beautiful to play such a damaged and plain character. However, while the film wasn't an enormous hit, Pfeiffer's performance was widely-praised and the actress was nominated for a Golden Globe as a result.