Director Shûsuke Kaneko did not speak any English at the time of filming his segment with an all American cast.
Jeffrey Combs was hesitant about portraying Lovecraft on film. "I don't look like Lovecraft" he commented, but makeup made him look like Lovecraft as best as they could. He also wasn't particularly fond of the direction they went with his rendition. There are shots where the makeup worn by Combs greatly resembles actor Bruce Campbell, right down to the scar on his chin.
This movie failed to get a domestic theatrical release. The film was financed by a Japanese and a French company. They released the film theatrically in their territories to recoup their investment. Then the rest of the territories were sold by a sales agent, August Entertainment. Without any prior investment in the production, New Line Cinema, which acquired distribution rights, decided that they were safer releasing direct-to-video rather than risking money on a theatrical marketing campaign. New Line Home Video released the film direct-to-video three years later.
Melinda Clarke was originally offered the role of Sarah.
At approximately the 37:30 minute mark (during "The Cold") some violin/synth cords are played as a part of the score. This tune is identical to the closing credits music of the TV show Dexter. Daniel Licht composed both scores. Dexter was released 13 years after Necronomicon.