Isolated traumatic supraclinoid internal carotid artery (ICA) dissection is a rare complication of blunt craniomaxillofacial trauma, and differentiation from atherosclerosis is the key factor for confirming the diagnosis.A 53-year-old man was admitted because of blunt trauma to his head and face. His primary manifestations were disability of abduction of the left eye on day 2, recurrent epistaxis and a blowing murmur in the left ear on day 4. Neurological physical examination showed bilateral normal pupil diameter, a corrected visual acuity of 0.6 in the right eye and 0.3 in the left eye, and loss of abduction of the left eye. Craniofacial computed tomography scans revealed multiple craniomaxillofacial fractures mainly including a LeFort III injury of the left maxilla, fractures of the left ramus of the mandible, fractures of the left orbital apex, fractures of the sellar turcica, etc. Brain magnetic resonance (MR) findings showed multifocal lacunar infarcts in the left hemisphere. Cerebral angiography demonstrated severe intraluminal stenosis of the left supraclinoid ICA, which was highly suspicious of arterial dissection. A high-resolution vessel wall MR imaging performed on day 7 showed proximal intramural subacute haemorrhage and two distal intimal flaps at the injured region, both of which facilitated the exclusion of atherosclerosis and thus, confirmation of isolated arterial dissection. The patient underwent treatment with endovascular stent placement and antiplatelet agents two weeks later and had no ictus of symptomatic stroke during the next half-year duration.HR vw-MRI is able to assist in the diagnosis of isolated traumatic supraclinoid dissection complicated with underlying atherosclerosis.