Evelyn Ankers hoped to do her own singing for the film, but because of the tight production schedule producer Ben Pivar used stock recordings of Lillian Cornell for the scenes in which Ankers' character sings (and the songs are obviously older recordings since their sound quality is inferior to the rest of the soundtrack).
"The Mad Ghoul" was the last film of director James P. Hogan, who finished the film in May. He died eight days before it was released on November 12,1943.
Isabel's song, "Our Love Will Live," uses the melody from Tchaikovsky's Piano Concerto #1.
Part of the original Shock Theater package of 52 Universal titles released to television in 1957, followed a year later with Son of Shock, which added 20 more features.
This was the only Universal horror film that touched upon the subject of Zombies.