Posttraumatic cerebral infarction is a recognized complication of craniocerebral trauma, but, its frequency, cause, and influence on mortality are not well defined. During a two year period, 706 patients with head trauma were examined in our hospital with cranial CT studies. The CT findings which strongly suggested the herniation were seen in 46 patients. The posttraumatic cerebral infarction was diagnosed retrospectively in 18 of these patients. Detailed information, including CT findings were recorded from 1 to 10 days after admission. Posttraumatic cerebral infarctions were seen in the vascular territories of the middle cerebral artery(PCA) in 9 patients, posterior cerebral artery(PCA) in 4 patients, anterior cerebral artery(ACA) in 3 patients, and multiple in 2 patients. Outcomes of these 18 patients were severely disabled in 8 patients, moderate disabled in 6 patients, and death in 3 patients. Only one remaining patient was demonstrated a good recovery. These results suggest that cerebral infarction with severe head trauma might be associated with significantly bad influence on outcome of these patients when compared with those without cerebral infarction.