We report on a 36-year-old patient with an acute cerebral infarction due to a spontaneous dissection of both internal carotid arteries in conjunction with type I osteogenesis imperfecta. Spontaneous dissections of cerebral arteries (DCA) represent a common cause of cerebral infarctions in younger patients. Our case shows that a hereditary connective tissue disorder should be considered in all patients with "spontaneous" DCA. The identification of an - initially unknown - hereditary connective tissue disorder may con-tribute to primary and secondary prophylaxis of cerebral ischemia.