We reviewed the records of the Chief Coroner for all pediatric (< 16 years of age) trauma fatalities in Ontario (pediatric population of 2 million) for the period January 1, 1988 through December 31, 1990. Forty-one (14.5%) of 282 patients for which complete autopsy data were available had sustained cardiac injuries. Nineteen patients (46%) died at the scene of the accident, 15 patients (37%) died in an emergency department, and seven patients (17%) died during hospitalization. Rupture of a cardiac chamber occurred in 16 cases; it was the main cause of death in eight cases and a contributing factor in the remainder. Cardiac contusion without chamber rupture was present in 25 cases, but in none of the cases was it the cause of death. Brain injury was the cause of death in 16 (64%) of the cases of cardiac contusion. Cardiac injuries are more common among children who die from blunt trauma than previous reports have suggested. However, because these injuries are often rapidly fatal, many patients die before they reach a hospital. With improvements in emergency medical services and the resulting reduction in transit time, more patients may reach trauma centers alive. A high index of suspicion and rapid diagnosis and treatment of these injuries can save the lives of some of these patients.