We examined the incidence and timing of posttraumatic cerebral infarction (PTCI) and provide predictive factors for the development of PTCI in patients with moderate or severe traumatic brain injury. Three hundred and fifty-three consecutive patients with moderate or severe head trauma were retrospectively reviewed to determine the incidence and timing of PTCI and to evaluate the effects of age, gender, admission Glasgow Coma Scores (GCS), decompressive craniectomy, brain herniation, and low systolic blood pressure (BP) on the development of cerebral infarction. Risk factors for posttraumatic cerebral infarction were evaluated using logistic regression analysis. PTCI was observed in 36 (11.96%) of the 353 patients, and in a majority of cases, cerebral infarction developed within 2 weeks after injury. Poor admission GCS (P<0.01), low systolic BP (P<0.01), brain herniation (P<0.05), and decompression craniotomy (P<0.05) were significantly associated with the development of PTCI. No relationship was found between PTCI and gender or increased age. Posttraumatic cerebral infarction is a relatively common complication in patients with head trauma that develops early in the clinical course. Low GCS, low systolic BP, brain herniation, and decompression craniotomy may be risk factors for PTCI in patients with moderate or severe traumatic brain injury.