Malnutrition is one of the major causes of increased morbidity and mortality among hospitalized patients. The availability of nutritional therapy for these patients has made clinicians aware of the need for reliable methods of nutritional assessment. A variety of anthropometric, biochemical, and immunologic parameters has been used as indicators of protein-calorie malnutrition. Recently, the concentration of several rapid-turnover visceral proteins (transferrin, thyroxine-binding prealbumin and retinol-binding protein) has been shown to be a very sensitive parameter for indicating both the efficiency of nutritional therapy and conditions of borderline protein intake in apparently healthy children. Likewise, several immunologic parameters (including T cells, delayed hypersensitivity response, and complement components) have been shown to correlate with morbidity, mortality risk, sepsis, and death.