Moyamoya disease occurring in Chinese has been inadequately described. Here we report 13 cases of this disease identified by review of 3,200 cerebral angiograms performed between August 1979 and March 1986. Nine were males and four were females; there were 12 adults (aged 34–51 years) and one child (aged 11 years). All had hemorrhagic strokes with one exception, a patient with an occipital infarction. Intraventricular hemorrhage was noted by computed tomographyin10; five of these emanated from the caudate nucleus. A localized hematoma without intraventricular hemorrhage was found in two. All 13 angiograms had smokelike basal anastomoses with various degrees of stenosis or occlusion of the anterior portion of the circle of Willis; the involvement was bilateral in 12 and unilateral in one. Aneurysms were found in two patients, one in the anterior communicating artery and the other in the left anterior choroidal artery. Eleven patients recovered from the initial stroke, but two died with recurrent hemorrhage. This series differs from the series reported in Japan by the predominance of adult males. The high incidence of intraventricular hemorrhage and intracerebral hematoma is not in keeping with the previous Chinese series, in which subarachnoid hemorrhage was suspected to be the major clinical manifestation. (Stroke1988; 19:53–59)