OBJECT Patients with traumatic brain injury (TBI) with low presenting Glasgow Coma Scale (GCS) scores have very high morbidity and mortality rates. Neurosurgeons may be faced with difficult decisions in managing the most severely injured (GCS scores of 3 or 4) patients. The situation may be considered hopeless, with little chance of a functional recovery. Long-term data are limited regarding the clinical outcome of children with severe head injury. The authors evaluate predictor variables and the clinical outcomes at discharge, 1 year, and long term (median 10.5 years) in a cohort of children with TBI presenting with postresuscitation GCS scores of 3 and 4. METHODS A review of a prospectively collected trauma database was performed. Patients treated at Riley Hospital for Children (Indianapolis, Indiana) from 1988 to 2004 were reviewed. All children with initial GCS (modified for pediatric patients) scores of 3 or 4 were identified. Patients with a GCS score of 3 were compared with those with a GCS score of 4. The outcomes of all patients at the time of death or discharge and at 1-year and long-term follow-up were measured with a modified Glasgow Outcome Scale (GOS) that included a “normal” outcome. Long-term outcomes were evaluated by contacting surviving patients. Statistical "classification trees" were formed for survival and outcome, based on predictor variables. RESULTS Sixty-seven patients with a GCS score of 3 or 4 were identified in a database of 1636 patients (4.1%). Three of the presenting factors differed between the GCS 3 patients (n = 44) and the GCS 4 patients (n = 23): presence of hypoxia, single seizure, and open basilar cisterns on CT scan. The clinical outcomes were statistically similar between the 2 groups. In total, 48 (71.6%) of 67 patients died, remained vegetative, or were severely disabled by 1 year. Eight patients (11.9%) were normal at 1 year. Ten of the 22 patients with long-term follow-up were either normal or had a GOS score of 5. Multiple clinical, historical, and radiological factors were analyzed for correlation with survival and clinical outcome. Classification trees were formed to stratify predictive factors. The pupillary response was the factor most predictive of both survival and outcome. Other factors that either positively or negatively correlated with survival included hypothermia, mechanism of injury (abuse), hypotension, major concurrent symptoms, and midline shift on CT scan. Other factors that either positively or negatively predicted long-term outcome included hypothermia, mechanism of injury, and the assessment of the fontanelle. CONCLUSIONS In this cohort of 67 TBI patients with a presenting GCS score of 3 or 4, 56.6% died within 1 year. However, approximately 15% of patients had a good outcome at 10 or more years. Factors that correlated with survival and outcome included the pupillary response, hypothermia, and mechanism. The authors discuss factors that may help surgeons make critical decisions regarding their most serious pediatric trauma patients.