This communication reports a southern Brazilian outbreak of acute hepatic insufficiency in which 14 dairy animals died after consumption of Dodonea viscosa. The clinical course lasted a few hours and was characterized by apathy and staggering disorders. The main postmortem findings occurred in livers as enhanced lobular patterns and hepatocellular necrosis that ranged from centrilobular to massive. Similar clinical and pathological effects were experimentally induced by dosing a heifer with 30 g/kg of the plant's green leaves.