The etiology of Moyamoya Disease (MMD) is unknown. It is a cerebrovascular disease which is caused by occlusion or stenosis and can be diagnosed by angiographic methods. Digital Subtraction Angiography (DSA) is the gold standard for diagnosis, especially in cases with mild stenosis and few collateral lesions. The causes of this disease are unknown; it is usually associated with congenital or tumoral defects. This disease is more common in the yellow race, especially woman in Japan. Its prevalence is low in countries other than Japan. The high prevalence of the disease in Japan has given it its name from Japanese. Moyamoya; Meaning of Japanese means smoke dispersing in the air.