This study population consisted of 30 patients of homozygous β-thalassemia and 30 patients with sickle cell disease. They were subjected to full history, clinical, laboratory and echocardiographic examination.Another 30 healthy children were selected to serve as controls, afterevaluation of our results, right ventricular diameter showed significant increase in dimension in sickle cell disease compared to controls, interventricular septal diameter, left ventricular posterior wall thickness, left atrial diameter, aortic diameter, left ventricular end-diastolic diameter and left ventricular end-systolic diameter, showed significant increase indimension in both groups compared to controls, systolic functionsshowed significant difference in both groups compared to controls, our patients showed no evidence of diastolic dysfunction, impairment in the peak velocity of early filling, while there was impaired relaxation pattern in sickle cell disease patients, pulmonary hypertension detected in 20% of β-thalassemia and 23.3% in sickle cell disease.