Until now, recommendations for nutrition therapy of HIV-infected subjects can only be regarded as preliminary, because of the lack of scientific results regarding the interactions between HIV-infection and nutrition. HIV-infected patients have a high risk to become malnourished during the course of the disease, as a consequence of multiple pathogenetic factors--similar to the nutritional problems of tumor patients. At the moment, the following procedure is recommended in order to treat or prevent HIV-associated malnutrition: The nutritional status and history should be assessed in each HIV-positive subject as early as possible. Independent of the actual nutritional status, each patient should obtain a nutrition education. A continuous nutrition therapy becomes necessary in the case of evident or imminent malnutrition. Nutrients should be applied by oral access as long as possible. But especially for patients with opportunistic infections of the GI-tract accompanied by malabsorption, total parenteral nutrition may be the only effective way of nutrition.