At present, encephaloduroarteriosynangiosis (EDAS) and encephalomyosynangiosis (EMS) are the treatments of choice for moyamoya disease in children, but no attempts have been made to determine which is the more effective procedure, for the ischemic lesions in moyamoya disease. Ten patients (seven children and three adults) underwent EDAS and/or EMS: three patients EDAS on both sides; seven patients EDAS on one side and EMS on the other. These ten patients were followed up with a neurological examination and r-CBF and angiographic studies. Postoperative angiograms and r-CBF studies demonstrated more revascularization from the external carotid artery in sides treated with EDAS than with sides treated with EMS. From these results, it is concluded that the EDAS surgical procedure is superior to that of EMS for moyamoya disease.