Twelve male Fisher 344 rats were fed corn naturally contaminated with Fusarium moniliforme. This corn sample was obtained from feed being fed horses during an outbreak of leukoencephalomalacia. All rats necropsied from 123 to 176 days post feeding had multiple hepatic nodules and pale depressed hepatic areas. Histological examination revealed multiple hepatic neoplastic nodules and large areas of adenofibrosis and cholangiocarcinomas. The corn only diet was deficient in many nutrients including choline and methionine. Aflatoxins at a level of greater than 0.9 p.p.b. were not detected. A discussion is presented regarding the significance of these lesions and possible relationship to the contaminating fungus and the choline, methionine deficient diet.