Trauma Score Systems attempt to summarize the severity of injury in a single value. They provide a better classification of trauma patients and translate different severities of injury in a common language. They enable thereby comparisons between hospitals or trauma systems. Young doctors can control their clinical judgement with scoring systems and will gain experience. Scoring systems therefore increase safety and can help in decision making. As accuracy of scoring systems is never 100% individual decisions can never rely on scores only. Glasgow Coma Scale, Revised Trauma Score, Injury Severity Score and TRISS are the most often used international scores for severely injured patients. Their sensitivity and specificity, validity, reliability and practicability have been studied and proved in many trials. The role of these scoring systems for quality management purposes in the treatment of severe trauma is actually studied with the Trauma Registry of the German Society for Trauma Surgery.