Moyamoya disease is a chronic non-inflammatory cerebrovascular steno-occlusive disorder of unknown origin, with a typical pattern of collateral netlike vessels visualized in angiography. In Poland it is a relatively rare condition. A case of a 44-year-old non-Japanese woman with moyamoya disease is presented. Ischemic manifestation of the disease, rather uncommon in adults, and a long asymptomatic post-operative period are discussed.