We describe a 54-year-old woman exhibiting MMS who developed delayed dural sinus thrombosis associated with PCD. Angiographic findings of the patient were so unusual that bilateral internal carotid arteries were occluded between their origin and the carotid fork with extensive development of collateral circulation via the external carotid arteries and the posterior cerebral arteries instead of moyamoya vessels at the base of the brain. Seven years after bilateral cerebral revascularization surgery, intracerebral hemorrhage occurred caused by dural sinus thrombosis. In the treatment for the patient with MMS associated with PCD, risk of sinus thrombosis should be taken into account. (c) 2005 Elsevier Inc. All rights reserved.