As the number of preventable trauma-related deaths plateaus as a result of trauma system development, new directions for quality improvement in trauma care must come from analyzing morbidity with standardized methods to establish thresholds for provider-related and disease-specific complications. To establish such thresholds and determine priorities for improvements in quality all trauma patients who died, who were admitted to the ICU or OR, who were hospitalized for more than 3 days, or who were interfacility transfers to an academic trauma service, were concurrently evaluated for 1 year. All complication events were defined, reviewed, tabulated, and classified using 135 categories of complications. These categories were subdivided into provider-specific and disease-specific complications. Provider-related complications were classified as justified or unjustified to allow identification of events with a potential for improvement. A total of 1108 patients were admitted (mean ISS, 17); there were 97 deaths. Three potentially preventable deaths were identified, 857 complication events were identified, and 285 provider-related complications were responsible for errors with potential for improvement in 59 events (21%). Disease-specific morbidity was primarily related to infection; pneumonia accounted for 36% of all infectious complications and systemic infection for only 8.6% of infectious complications. Organ failure and other major systemic complications occurred in 2%-8% of patients. This type of analysis forms the basis on which to determine thresholds of provider-specific and disease-specific morbidity in a trauma hospital and serves as a guide to direct efforts toward continuous quality improvement.