The film's source material, "The Invisible Host", was a novel by the husband and wife team of Gwen Bristow and Bruce Manning. Their whodunit was inspired by a neighbor whose raucous radio disturbed them day and night. The novel begins: "That makes thirty-seven words, said the girl. Will you read the telegram again? came the voice over the wire. She read: Congratulations stop plans afoot for small surprise party in your honor Bienville penthouse next Saturday eight o'clock stop all sub rose big surprise stop maintain secrecy stop promise you most original party ever staged in New Orleans Signed Your host." The stage version, "The Ninth Guest", was written by Owen Davis. The Broadway production opened at the Eltinge 42nd Street Theatre in New York on August 25, 1930, and ran for 72 performances. The opening night cast included Berton Churchill, William Courtleigh, Alan Dinehart Grace Kern, Frank Shannon, and Robert Vivian.
The centerpiece of the film's Art Deco penthouse is a grandfather clock concealed behind a curved wall except for the face of the clock and the bottommost tip of the pendulum, which swings ominously within a smile-faced window of light.
At first glance, mystery aficionados might assume that Owen Davis borrowed heavily from Agatha Christie's "Ten Little Indians" in the plotting of The Ninth Guest. But the stage play on which this film was based was produced in 1930, nine years before Christie's novel was published, which suggests it was Christie who based the framework of her groundbreaking tale on The Ninth Guest.
The novel on which this film was based, "The invisible Host" was written by the husband and wife team of Gwen Bristow and Bruce Manning in their New Orleans home at 627 Ursuline Street in the French Quarter. This was their first novel and was inspired by a neighbor who played his radio loudly at all hours of the day and their imagination of how they wished him dead.
Whilst the poster gives the title as "The 9th Guest", the opening credits have it as "The Ninth Guest".