A young man with cerebral infarction, skeletal, cardiac and renal malformations was found to have on angiography a rare lesion involving the cervical left internal carotid artery, formed by the superposition of two arterial lumina. Anti-platelet therapy did not prevent thrombosis of the lesion and reinfarction. Extracranial-intracranial bypass graft was performed, followed by excision of the arterial lesion. Pathological examination revealed fibromuscular dysplasia and dissecting aneurysm. The few reported cases associating fibromuscular dysplasia of the internal carotid artery with dissecting aneurysm are reviewed. Surgical therapy is recommended in such cases when symptomatology progresses. Fibromuscular dysplasia occasionally coexists with somatic malformations, suggesting a congenital origin of this condition.