This study evaluated the effects of acquired immunodeficiency syndrome wasting syndrome (AWS) on the heart in a population free of overt opportunistic infection or clinical evidence of cardiac disease. Data from 53 patients with AWS and 16 healthy age-matched controls were studied. By echocardiography, a significant reduction in left ventricular mass was found in patients with AWS that remained significantly reduced when corrected for body surface area. Mean ejection fraction was within the normal range in patients with AWS but was significantly less than in controls. End-systolic volume index was slightly elevated in patients with AWS. Although no difference in end-systolic wall stress was seen, the end-systolic wall stress-shortening relation differed significantly. These findings are consistent with myocardial atrophy and subtle left ventricular dysfunction in patients with AWS.