A description of the clinical signs and pathological changes is given of 2 outbreaks of suspected hybrid vetch poisoning in the Humansdorp district, Republic of South Africa. These were characterised by a severe dermatitis, high morbidity and mortality in older cows. Microscopically granulomatous lesions occurred in the kidneys, liver, myocardium, spleen and skin. Variable numbers of multinucleated giant cells and eosinophils were seen in these lesions. Acute multifocal hepatic necrosis was observed in 2 animals. Brief comparisons are made with outbreaks of vetch poisoning in other parts of the world.