The term moya-moya encompasses two clinical scenarios, moya-moya disease and moya-moya syndrome. Pathological changes have been found in both intracranial and extracranial arteries, suggesting that moya-moya is not an isolated intracranial arteriopathy. The familial occurrence of moya-moya disease and the much higher rates of the disease among persons of Japanese ancestry point towards a genetic factor. While brain imaging, especially magnetic resonance imaging (MRI), provides clues for the diagnosis of moya-moya, vascular imaging, especially conventional arteriography, remains the standard way to assess the presence, location, and extent of the arterial abnormalities. Prevention of recurrent stroke is the focus of management of patients with moya-moya. Direct or indirect revascularization procedures should be offered early in the course of the illness in order to prevent recurrent ischemic stroke. Antiplatelet agents are prescribed. Due to the potential of bleeding complications, oral anticoagulants usually are avoided.