Parameters thought to reflect nutritional status were assessed in 25 critically ill postoperative patients who had been acutely injured. Results were compared with those from a group of 28 critically ill postoperative patients who had not sustained trauma. The anthropometric measures were significantly better preserved in the previously healthy and presumably well-nourished trauma patients, but striking abnormalities were observed in both groups in albumin and transferrin levels, in the lymphocyte count, and in skin test reactivity. The latter findings suggest the influence of non-nutritional factors at least in the acutely injured patient.Anergy, although frequently observed in both groups of patients, was not predictive of mortality nor did the 44 surviving patients differ significantly in any of the other measured parameters from the nine patients who died.We conclude that, at present, the need for nutrition therapy for the acutely injured patient is best determined on traditional clinical grounds.