Ischaemic complications are common in SS homozygotic sickle cell disease in children, but the heart does not appear to be the target organ. The early detection of myocardial ischaemic in these children could prevent cardiac complications. The authors undertook a study of myocardial perfusion by myocardial scintigraphy in children with sickle cell disease. Twenty-three patients (average age 12 +/- 5 years) underwent Thallium 201 myocardial scintigraphy. Exercise on a bicycle ergometer and/or intravenous injection of dipyridamole were carried out depending on the age. The images (on exercise and late recovery period) were analysed in the 3 standard projections of the left ventricle: short axis, long axis and 4-chamber view. The left ventricular ejection fraction was measured by gamma angiography. Myocardial perfusion was abnormal in 14 patients (61%). The perfusion defects were reversible in the late recovery period in 9 patients and irreversible in 5 patients. The average left ventricular ejection fraction was 63 +/- 9%. Its value was not related to symptoms, haemoglobin level or the results of myocardial scintigraphy. Four patients with perfusion defects were symptomatic (cardiac failure, angina or ventricular tachycardia); 1 patient died and 3 were treated with hydroxyurea. Myocardial scintigraphy was carried out 6 months later and showed improved perfusion in 3 patients. Abnormalities of myocardial perfusion are therefore common in sickle cell disease. Often asymptomatic in childhood, there is a real risk of ischaemic cardiomyopathy and its complications in adulthood. Specific treatment of sickle cell disease with hydroxyurea should be considered in cases with significant abnormalities of myocardial perfusion.