Dissecting aneurysms of the extracranial cervical arteries in Marfan's syndrome are most frequently caused by the extension of aortic dissection. Spontaneous and isolated aneurysms limited to the major extracranial cervical arteries have also been reported in Marfan's syndrome, although very rarely. In these cases, the aneurysms are usually asymptomatic or may present as a pulsatile mass. Transient ischemic attacks (TIAs) or strokes, associated with isolated extracranial aneurysms, have not been mentioned in Marfan's syndrome. We report a patient with Marfan's syndrome presenting with TIAs in whom we detected a saccular aneurysm of the vertebral artery as well as bilateral fusiform aneurysms of the internal carotid arteries.