The study was conducted in the emergency department of a suburban, tertiary care, university-based medical center. Patients were eligible for the study if they were between the ages of 13 and 18 and presented to the emergency department during 1998. The medical records of such patients were screened daily to identify those presenting with a traumatic injury or a toxic ingestion. Data collection encompassed the patient's age, gender, race, diagnosis, etiology and mechanisms of injury, and disposition. All written notes were reviewed to determine whether there was any notation on the presence of precipitating events or emotions. The investigator noted whether an injury was the direct result of self-infliction due to anger and what caused the anger. During the study period, 43,370 patients were examined in the emergency department, and 3,370 of these were between the ages of 13 and 18. Of 1,702 cases of traumatic injuries in this age group, 214 (12.4 percent) were self-inflicted in response to anger stimulated by an argument or interpersonal conflict. A total of 165 of this number were males, and 49 were females. The study concludes that the prevalence of such injuries self-inflicted under conditions of uncontrolled rage warrants further research and preventive interventions that target this specific behavior. A better understanding of this problem should lead to the development of effective methods for helping juveniles to manage their anger constructively. 1 table and 11 references