Hospital trauma registries are evolving rapidly as a result of a renewed focus on trauma care evaluation and recent advances in microcomputer technology. In theory, trauma registries can serve as the principal tool for the systematic audit of the quality of patient care provided by a hospital or a trauma system and as a potential source of part of the data needed for injury surveillance. In practice, however, there is a tendency to underestimate the resources needed to initiate and maintain a registry. Herein, we describe the purposes, resource requirements, and limitations of trauma registries. We conclude that standardization of case criteria, core data content, data definitions, and coding conventions can enhance the utility of trauma registries.