Cladosporium flavum, a fungus which has an parasitic action on other fungi can be used to inhibit the growth of Aspergillus parasiticus, a mold which produces aflatoxin. C. flavum can totally inhibit A. parasiticus, as shown by experiments using artificial recovery media with peanut, rice and corn infusions, if it has been inoculated into the infusions a week before A. parasiticus inoculation.