A three-valued description of anatomic injury is presented. Anatomic profile (AP) components A, B, and C summarize serious injuries ( > AIS 2) to the head/ brain or spinal cord; to the thorax or front of the neck; and all remaining serious injuries. Relationships between AP components and survival rate reaffirm the seriousness of head injury. Logistic function models relating AP components and the Injury Severity Score (ISS) to survival probability were based on 20,946 Major Trauma Outcome Study (MTOS) patients (9.2 mortality rate) submitted through 1986. Model performance comparisons were based on 5,939 MTOS patients (7.8 mortality rate) submitted during 1987. The AP better discriminated survivors from nonsurvivors and provided a 31 increase in sensitivity when compared with the ISS. Neither the ISS nor the AP alone reliably predict patient outcome. The predictive power of methods for estimating patient survival probability which include physiologic indices or profiles, patient age, and an anatomic profile should be compared with current methods. The AP, which is based on the severity and location of all serious injuries, provides a more rational basis for comparing patient samples than the ISS.