Given the negative effect of malnutrition on the immune function, the possibility must be considered that this also affects the clinical progression of AIDS patients. This study was aimed at assessing the state and nutritional support indicated for patients diagnosed as having AIDS. 114 patients admitted to our hospital in the period 1990-1991 were studied, with assessment of the nutritional state by means of anthropometric parameters (weight, size, tricipital fold, arm muscle circumference), biochemical parameters (albumin, lymphocytes, transferrin, RBP) and the treatment prescribed. Average age was 31.44 +/- years, 81.5% were male, 68% parenteral drug addicts. 71% had a stage IV C diagnosis. 37.72% had diarrhea before beginning treatment. The malnutrition diagnosed was as follows: moderate, 50.89%, severe 36%, slight, 12.5%, and mixed (calorific-protein), 62.5%, calorific 34.8%, and protein 2.6% of cases, 33% of the patients received dietary supplements, 33.84% enteral alimentation and 33% parenteral alimentation. Nutritional support was suspended as follows: improvement, 54.46%; transfers, 1.79%; death, 27.68%, and terminal situation, 16.07%. Deceased or terminal patients were more severely malnourished (p < 0.001) than the remainder. AIDS patients are studied and treated nutritionally in a very advanced stage of the illness, with severe malnutrition which conditions a poorer evolutive diagnosis. This suggests a change of attitude, with assessment being necessary of nutritional state and the appropriate therapy at the time of diagnosis, in order to slow the progression of the illness.