The objective of this study was to obtain representative echocardiographic measurements of cardiac size and function in stable patients with sickle cell disease. This prospective, multicenter study utilized central reading of echocardiograms by an investigator blinded to other patient data. Stable outpatients from a balance of inner city and rural settings with SS phenotype and a broad age range were selected, because conflicting results from earlier studies were believed to be due to these patient selection criteria. Right and left ventricular dimensions and wall thickness, left atrial and aortic root dimensions, and systolic time intervals were measured. Body surface area indexed chamber dimensions and septal thickness were significantly increased from normal. Except for the right ventricle, chamber dimensions and wall thickness were inversely correlated with hemoglobin. The relationship between left ventricular dimension and hemoglobin was significantly dependent on age. Systolic time interval ratios were normal though left ventricular ejection time was prolonged. Shortening fraction was normal but velocity of circumferential fiber shortening was abnormally low. Stable patients with sickle cell disease have dilated chambers, septal hypertrophy, and normal contractility. Though left ventricular dilatation was inversely related to hemoglobin, age (duration of illness) was an important factor in that relationship. No specific cardiomyopathy was associated with sickle cell anemia.