Four-week-old male broiler chickens were intubated with a single dose of purified T-2 toxin at 2.5 mg/kg body weight. The brain concentrations of dopamine (DA), norepinephrine (NE), and serotonin (5-HT) and selected blood components were determined in T-2 toxin treated and control chickens at 4, 12, 24, and 48 hr after the toxin treatment. The brain DA concentration of T-2 treated chickens was significantly greater at 12 and 24 hr, whereas brain NE was lower at 24 and 48 hr after toxin treatment as compared with controls. The brain 5-HT level was not altered by T-2 toxin. Serum cholesterol was increased at 4 and 12 hr after T-2 treatment. The serum LDH and GOT activities were not changed by T-2 toxin. T-2 treated chickens had greater packed cell volume and hemoglobin than controls at 24 hr after dosing. Red blood cell counts were not affected but white blood cell counts were decreased during the 12 to 48 hr period after T-2 treatment. The results of this study suggest that T-2 toxin influences brain catecholamines and blood components and thereby possibly brain function in chickens.