This chapter introduces injury severity scoring systems available for pediatric trauma patients. The injury scoring systems are presented within a conceptual framework based on three primary areas of applicability: (1) prehospital triage, (2) clinical decision support in the emergency department, and (3) research and quality improvement. Each scoring system is briefly described, and its performance as a clinical decision support metric is evaluated. Clinical decision-making in the acute setting is addressed in another chapter of this book, so we will focus on scoring systems evaluating injury severity in the 3rd conceptual framework described above. Scoring systems that are primarily utilized in research and quality improvement efforts tend to be more comprehensive and precise. However, they often require many additional datapoints and are therefore typically unwieldy and labor-intensive scoring systems that are only applicable in a retrospective evaluation of injury severity. While there was insufficient evidence to recommend a specific scoring system for research and quality improvement in pediatric trauma, we will discuss some of the available systems and their relative merits. Future severity metrics in pediatric trauma should focus on risks of resource utilization rather than on mortality.