Fusariotoxin T-2 is a mycotoxin produced by Fusarium tricinctum which was implicated in moldy corn toxicosis of farm animals. Graded concentrations of dietary fusariotoxin T-2 (0, 1, 2, 4, 8, and 16 μg/g, respectively) were given to groups of 40 chickens. Raised yellowish-white lesions on the mouth parts were produced by all concentrations, and the size of the lesions was dose-related. The growth rate was reduced significantly (P < 0.05) by concentrations of 4, 8, and 16 μg/g. The mouth fluid of the affected birds contained greatly increased numbers of bacteria, including Staphylococcus epidermidis and Escherichia coli, which proved avirulent when inoculated into scarified tissue of control birds. Microscopy examinations of the lesions revealed a fibrinous surface layer, intermediate layers containing invaginations filled with rods and cocci, and a heavy infiltration of the underlying tissues with granular leukocytes. These data suggest that the role of fusariotoxin T-2 in field cases of moldy corn toxicosis should be reinvestigated since oral lesions were not mentioned in the original descriptions of the disease. However, the lesions bear some features of those characteristic of the third or septic angina stage of alimentary toxic aleukia, a nutritional toxicosis of humans produced by eating grains infested with F. tricinctum. Images