A 13-year-old girl with psoriasis of the elbow, trunk, and face suddenly developed a severe headache followed by left hemiparesis and facial palsy. Brain magnetic resonance imaging showed an acute infarction of the right temporofrontal lobe and basal ganglia on the T2- and diffusion-weighted images. Cerebral angiography showed pre-occlusive irregular scalloped stenosis (99%) in the proximal M1 segment of the right middle cerebral artery and a web-like stenosis at the supraclinoid portion of the right internal carotid artery (ICA) suggestive of a spontaneous intracranial ICA dissection. The patient was administered a low dose of dipyridamole, and a rehabilitation program was initiated. Headache, left motor weakness, and facial droop improved within a week. However, mild left facial palsy and reduced fine motor function of the left hand were still present after 3 weeks. We report a rare case of spontaneous intracranial ICA dissection in a child with psoriasis.