The purpose of this study was to identify the causes and time to death of all trauma victims who died at a level I trauma center during an 11-year period.Autopsies were performed on all patients who died secondary to trauma. Retrospective review of these autopsies was carried out and appended to existing trauma registry data. Standard definitions were used to attribute the cause of death in each case. Preventable deaths were determined by a standardized peer review process.Between January 1985 and December 1995, a total of 900 trauma patients died. This represented 7.3% of all major trauma admissions (12,320). Seventy percent of these patients died within the first 24 hours of admission. Thoracic vascular and central nervous system (CNS) injuries were the most common causes of death in the first hour after admission to the hospital. CNS injuries were the most common causes of death within the 72 deaths after admission. Acute inflammatory processes (multiple organ failure, acute respiratory distress syndrome, and pneumonia) and pulmonary emboli were the leading causes of death after the first 72 hours. Overall, 43.6% (393 of 900) of all trauma deaths were caused by CNS injuries, making this the most common cause of death in our study. The preventable death rate was 1%.The first 24 hours after trauma are the deadliest for these patients. Primary and secondary CNS injuries are the leading causes of death. Prevention, early identification, and treatment of potentially lethal injuries should remain the focus of those who treat trauma patients.