Reducing mortality among accident and trauma patients requires careful attention to monitoring those regarded as being at low risk. We hospitalized almost 1600 head-injured patients in the period between 1979 and 1992 at the Neurosurgery Department of Gazi University Medical School, Ankara, Turkey. These patients were selected from among the numerous patients admitted to our emergency unit and treated with the same protocol in the same department. Among the hospitalized children, there were three patients defined as having a mild head injury on the basis of Glasgow Coma Scale scores of 15 who later had unfavorable outcomes. Clinical signs that might identify potentially endangered patients with mild injury were gathered; these included the presence of post-traumatic amnesia, somnolence, irritability, anisocoria, local evidence of trauma to the head, associated injuries, history of altered consciousness, and skull fracture. The study was designed to identify features by which patients who are in real danger can be distinguished among the many with trivial trauma that we face every day. We did not find any identifying clinical features and concluded that computed tomographic scanning is the only reliable answer. This will reduce avoidable mortality and morbidity by identifying the patients who are at higher risk than is at first evident.