Uremic patients undergoing hemodialysis are often catabolic and malnourished. To treat malnutrition effectively, a preliminary nutritional assessment is needed. Available techniques should enable the clinician to readily detect the presence of malnutrition and to follow the response to nutritional therapy. In a group of chronic uremic patients undergoing maintenance hemodialysis, the authors evaluated the nutritional status with the following indices: 1) assessment of the somatic fat and protein compartments by means of anthropometric measurements (weight/height ratio, triceps and subscapular skinfold thickness, and arm muscle circumference); 2) assessment of the visceral protein compartment (serum total protein, albumin, transferrin, pseudocholinesterase, C3, and immunoglobulin content); 3) assessment of cell-mediated immunity by means of skin tests ("skin window," PPD and phytohemagglutinin) and blood lymphocyte content; and 4) assessment of the dietary intake of nutrients with dietary diaries. Anthropometric indices, serum protein content (except immunoglobulins), and the immune response was generally lower than in normal subjects, suggesting a mixed marasmus-like and kwashiorkor-like pattern of protein-calorie malnutrition. The protein intake was normal, whereas the energy intake tended to be low. Protein intake was significantly correlated with the predialysis serum urea nitrogen. Due to the difficulties in improving oral energy intake and the negative nitrogen balance reported during the days of dialysis therapy, patients were given intravenous supplements of essential or essential and nonessential amino acids for 2 months. The effects of this short-term supplementation were limited.