When oral or enteral feeding becomes impossible or inadequate, total parenteral nutrition makes it possible to reduce the occurrence of malnutrition states as complications of medicosurgical disorders. From a practical point of view it should provide a minimum fluid intake of 30 ml/kg with a nitrogen intake of the order of 150 to 300 mg/kg/day with sufficient quantities of all essential amino acids in a balanced ration. In most instances the calorie intake should be 40 to 60 Kcal/kg/day. Non-protein calories are obtained from carbohydrates or fats but the ideal percentage of each of these two nutrients is not known. In order to be effective and well tolerated, intravenous nutrition of this sort must be adapted to each patient and should be administered by a qualified medical and nursing team in order to minimise the metabolic and septic risks secondary to the techniques used.