Moyamoya disease is a progressive cerebrovascular disorder, characterized by brain hypoperfusion resulted from gradual stenosis of the majority of cerebral arteries at the base of brain and development of a collateral basal vascular network. The etiology of the above disease is still unknown. This is a slowly progressive disease with a quite rare involvement of vessels of the vertebrobasilar system. There are two types of disease, idiopathic (from birth) and symptomatic (acquired). According to literature data, there is high probability of association between moyamoya disease and brain disgenesy, angiopathy, Down syndrome, homocystinuria, von Recklinghausen neurofibromatosis, sickle cell disease etc. It may also develop following basal meningitis. In some cases disease develops after cranio-cerebral traumas (up to 9%). Pathophysiologically, moyamoya disease is caused by morphological and functional factors. Morphologically, it manifests as stenosis, thrombosis and also subarachnoidal and intracerebral hemorrhages.