Alfred Hitchcock said he had to overcome fierce resistance from obstinate TV executives in order to present this story.
In the original short story, the proprietor was a man, and he did not allow women in his restaurant. Hitchcock changed both of these plot elements to appeal to a wider audience.
The teleplay was adapted from a short story of the same name written by mystery novelist Stanley Ellin (1916 - 1986). Ellin wrote the story in 1948, and it was his first published work.
In the original short story the restaurateur's name is Sbirro. For some reason the producers altered it to Spirro. This may have been to match the name of the actress, Madame Spivy, a well-known New York nightclub owner and pianist who was making her acting debut. The scene where she plays piano for the restaurant patrons is likely an in-joke about her career.