This study describes the cardiac size and function of patients with sickle cell anaemia, in Segipe, Brazil, and its association to the clinical severity, duration of illness and haemoglobin levels. Heart measurements were obtained by echocardiography from 38 children and adolescents and compared to international reference values. Sickle cell patients had increased left atrial and ventricular dimensions in systole and an increased end diastolic septal and left ventricular free wall thickness. These findings correlated with age. There were no abnormalities in the ejection or shortening fractions. These results suggest early haemodynamic changes with progressive cardiac chamber dilation and diastolic dysfunction that become increasingly abnormal with growth.