Fluoroacetate was dosed per stomach tube to 17 Merino sheep at the rate of 0,05-1,0 mg/kg/day. The clinical signs, haemodynamic changes, chemical pathology and pathology of acute, subacute and chronically intoxicated cases are described. Tetanic convulsions were seen in acutely intoxicated animals and in them respiratory failure, occurring concomitantly with cardiac failure, may have been the cause of death. Subacute intoxication resulted in less conspicuous clinical signs when the sheep were at rest, but they developed apparent nervous signs on being handled, and later tended to lie down. Chronically intoxicated animals were only mildly affected. At all levels of intoxication changes in the chemical pathological parameters were either absent or were mild and transient. The microscopic lesions in the hearts of acutely intoxicated sheep included degeneration as well as necrosis of individual or small groups of myocardial fibres. In the subacutely and chronically intoxicated animals the multifocal myocardial lesions were more widespread and in various stages of development or resolution.