The trial includes approximately 130 children (5.0-18.9 years of age with 65 subjects per treatment arm) with SCA who have had symptomatic cerebral infarctions and have been treated with red cell transfusions for at least 18 months. After completing baseline screening studies, half the participants will be switched to a therapeutic program of hydroxyurea and phlebotomy. Half of the participants will remain on transfusion and chelation. The composite primary endpoint in this study is to compare two modalities of treatment for the prevention of secondary stroke and management of iron overload. The impetus for this trial is the fact that long-term transfusion and chelation therapy in children is difficult, is frequently unsuccessful, and is often complicated by severe symptomatic iron overload, particularly of the heart, lungs, and liver.