Benefit achieved through use of angiotensin converting enzyme (ACE) inhibitors in patients with reduced left ventricular (LV) systolic function is not confined to those with clinical manifestations of heart failure. Although rates of adverse clinical events are lower in asymptomatic patients, within this population ACE inhibitors have been shown to prevent adverse ventricular remodelling prevent the development of clinical heart failure, reduce rates of hospitalization for heart failure and, in some studies, reduce mortality. Most of the benefit derived appears to be associated with preventing the progression of LV hypertrophy, dilatation, and dysfunction, resulting in prevention of heart failure. Additionally, the incidence of myocardial infarction is decreased although the exact physiological basis for this benefit remains uncertain. Given the enormity and growth of heart failure as a public health problem and the potential for influencing the underlying pathophysiology, ACE inhibitor treatment offers substantial benefit for patients with asymptomatic LV systolic dysfunction.