Severe anorexia nervosa in which psychiatric treatment has failed is a life-threatening condition since the degree of emaciation can be profound. Nine young women with a weight loss of 25-50% of their habitual weights were given total parenteral nutrition (TPN) over 3-8 weeks through a tunneled central venous silicone catheter. They initially received a mean of 55 kcal/kg body weight/24 hours increasing to 65-70 kcal/kg body weight during the first week. The initial bradycardia and hypotension were normalized and body weight increased with a mean of 2.5 kg/week. All patients showed a general somato-psychic improvement after two weeks of TPN. The electrolyte disturbances seen at the beginning were normalized during the first weeks of treatment and the previously reported life-threatening electrolyte disturbances and dehydration in connection with TPN treatment were not seen. The only adverse effect registered was a rise in liver enzymes in two patients who were given greater than 80 kcal/kg and day. With a reduction of the caloric supply these changes normalized, and TPN could be continued. After 3-8 weeks the oral intake had normalized and TPN was discontinued. This study confirms that TPN can be used successfully and with minimal risk in severe anorexia nervosa until the patients have normalized their oral intake.