The study comprised 100 ischemic stroke patients of both sexes aged 15-45 years who were treated at the Clinic of Neurology of the Clinical Center of Vojvodina in the period January 2001-September 2004. All study subjects were divided into three age groups: 15-25, 26-35 and 36-45 years. Sex, age and risk factors for cerebrovascular disease were determined in all patients. Diagnostic procedures applied in all patients included brain computed tomography and/or magnetic resonance imaging, routine laboratory tests, Doppler imaging of extra and endocranial blood vessels and coagulation tests. Contrast and/or transesophageal echocardiography, immunological blood assays, magnetic resonance angiography and/or computed tomography angiography and/or conventional angiography, thrombophilia markers, antiphospholipid antibodies and toxicological examination, etc. were performed in selected patients. Non-atherosclerotic arteriopathies were found in 8% of all study subjects, and were the most frequent cause of stroke in the age group 15-25. Carotid artery dissection was the most frequent diagnosis overall, found in 6% of all patients. Fibromuscular dysplasia and systemic vasculitis were diagnosed in one patient each. Moyamoya disease, Takayasu disease, infectious and isolated vasculitis of the CNS were not found in our patients.