We reviewed the coroner's records for all pediatric (less than 16 years of age) trauma fatalities in Ontario (population, 9.5 million) for the period January 1, 1985, through December 31, 1987. Twenty-six (8%) of the 322 cases for which complete autopsy data were available had major thoracic vascular injuries. Twenty-five deaths occurred within 6 hours of injury. The majority of patients had at least one AIS 6 injury. The aorta was the most frequently injured vessel. Major thoracic vascular injuries are more common among children than previous reports suggest, probably because they are rapidly fatal. Many deaths occur in the field, at local hospitals, or in transit before the patient can reach a trauma center. Efforts to reduce the number of total thoracic vascular injuries should focus on primary and secondary prevention.