Two organotin compounds, tri-n-butyltin acetate (TBTA) and triphenyltin acetate (TPTA), that have antifungal potentials and are intended for use on yam root crops to prevent rot were evaluated for acute mammalian toxicity in rats. The median lethal doses po were 297.54 mg TBTA/kg and 402.38 mg TPTA/kg. Both compounds produced significant central nervous system and respiratory depressions at single doses of 200 mg TBTA/kg or 300 mg TPTA/kg. The histopathological findings due to TBTA included pulmonary, hepatic and renal congestion, brain hemorrhages, and destruction of the intestinal mucosa. TPTA produced brain congestion, and hepatic and pulmonary petechial and generalized hemorrhages.