Angiotensin-converting enzyme (ACE) inhibitors effectively interfere with the renin-angiotensin system and exert various beneficial actions on cardiovascular system beyond their blood pressure-lowering effects. Controlled clinical trials have shown that ACE inhibitors improve endothelial function and vascular remodelling, and reduce the risk of myocardial infarction, stroke, and cardiovascular death. Data from experimental studies showed that ACE inhibitors can attenuate the development of atherosclerosis in a wide range of species. Further studies are needed to better understand pathophysiological mechanisms involved in vascular protection induced by ACE-inhibitors. ACE inhibitors have been used extensively in the management of patients with hypertension and heart failure. Over the past decade, a large body of evidence has emerged indicating that ACE inhibition also favorably affects the vasculature, and that these effects are associated with improved patient outcomes. Such evidence is provided by several sources: (i) experimental studies, which demonstrate that in addition to blood pressure lowering, ACE inhibitors improve endothelial function and have a host of other beneficial effects on the arterial wall; (ii) epidemiologic studies, which link the reninangiotensin- aldosterone system to increased risk for myocardial infarction, and (iii) clinical trials, which demonstrate that treatment with these agents reduces the risk for acute ischemic events, improves the function of the arterial endothelium and can retard the progression of the anatomic extent of atherosclerosis.