Abstract The effects of converting-enzyme inhibition by perindoprilat (0.5 mg/kg, intravenously, short-term administration) or perindopril (2 mg/kg, orally, long-term administration once a day for 21 days) on systemic and regional hemodynamics were studied on a new rat model of heart failure, which was induced by microembolization of coronary vessels by 15 μm plastic microspheres. Cardiac output and regional blood flows were measured by microsphere technique; the tone of the venous vessels was determined as mean circulatory filling pressure in conscious, freely moving rats. Perindoprilat evoked a much more prominent increase in kidneys, adrenal glands, intestine, and skin blood flows in embolized rats than in sham-operated rats. The differences between the effects of long-term treatment with perindopril in sham-operated and embolized rats were highly significant. Mean circulatory filling pressure was decreased by short-term and long-term administration of an angiotensin-converting enzyme inhibitor. It is concluded that venous vessels could be one of the target sites for the effects of perindopril-like drugs.