21 young female and 15 young male patients with cerebrovascular insults were examined for risk factors. 14 of the 15 male patients showed clear cut risk factors: obesity, diabetes, hyperlipidemia, arterial hypertension, smoking, thromboses, vitium cordis. 20 of the 21 female patients took oral contraceptives. 60% of the female patients with angiographically confirmed stenoses and occlusion did not show any other risk factor. These results support the hypothesis that oral contraceptives are in themselves a risk factor.