BACKGROUND: The aim of this study was to evaluate the demographics, mechanisms, pattern, injury severity, and the outcome (ie, length of intensive care unit [ICU] stay, length of mechanical ventilation, total length of stay, mortality) in multiple-injured children based on a review from the German trauma registry study ("Traumaregister") of the German Society of Trauma Surgery (Deutsche Gesellschaft für Unfallchirurgie e.V.). METHODS: One hundred three German trauma centers took part in the German trauma registry study from January 1997 to December 2003. Five hundred seventeen children (aged 0-15 years) with multiple injuries and an Injury Severity Score of more than 15 in comparison to 11,025 adults were included. Sex, age, and mechanisms and pattern of injury were assessed. The mechanisms of trauma and the anatomical distribution of severe injury (Abbreviated Injury Scale of 3 or more) were analyzed. The Injury Severity Score, the Revised Trauma Score, and the Trauma Score Injury Severity Score were calculated to estimate the severity of injury and mortality. RESULTS: The predominant sex was male. Most cases were caused by traffic-related accidents. Head injuries were most common in children, and severe thoracic injuries increased with age. Mean length of ICU treatment, mechanical ventilation, and total length of stay were shorter in children than in adults. A total of 22.6% of the children aged 0 to 5 years died in the hospital in comparison with in-hospital mortality rate of 13.7% in the 6- to 10-, 20.3% in the 11- to 15-, and 17.0% in the 16- to 55-year-old patients. CONCLUSIONS: There were differences between multiple-injured children and adults concerning injury mechanisms and pattern of injuries. Adults needed a longer mechanical ventilation and a longer ICU therapy. Most deaths could be seen in the youngest patients aged 0 to 5 years.