Aflatoxicosis was diagnosed in a small herd of cattle having access to moldy, unharvested sweet corn. Necropsy of 1 cow that died revealed anasarca and a pale tan liver. In this cow, microscopic examination revealed edema of all soft tissues and liver lesions consistent with aflatoxicosis. Samples of corn taken from the field contained 2,365 ng of aflatoxin/g of corn. Weather conditions were conducive to the formation of aflatoxins by Aspergillus flavus and A parasiticus.