The effect of a high energy missile trauma on energy metabolism and tissue oxygenation in uninjured parts of skeletal muscle was studied in anaesthetized pigs up to 72 hours after the trauma. High energy phosphates (HEP) were measured in muscle biopsies, and muscle tissue oxygenation was measured as muscle surface oxygen pressure fields by an oxygen electrode. In the traumatized group significantly decreased levels of HEP were found in spite of normal tissue oxygenation 72 hours after the trauma. In the control group both the HEP and the muscle tissue oxygenation were unchanged compared to the pretrauma situation. Decreased synthesis of HEP due to tissue hypoxia or inadequate nutrition could not account for the difference between the control and the trauma group. It was suggested that hypermetabolism induced by the high energy trauma caused increased utilization and thereby decreased concentrations of the HEP 72 hours after the trauma. It was also concluded that the general posttraumatic metabolic changes found in uninjured parts of the muscle tissue differed from the local changes of traumatized muscle described by other investigators, and therefore probably were caused by other mechanisms.