An economic analysis accompanied a multicenter Department of Veterans Affairs randomized, controlled trial of perioperative total parenteral nutrition (TPN). The cost of providing TPN for an average of 16.15 days before and after surgery was $2405, more than half of which ($1025) included costs of purchasing, preparing, and delivering the TPN solution itself; lipid solutions accounted for another $181, additional nursing care for $843, and miscellaneous costs for $356. Prolonged hospital stay added another $764 per patient to the $2405 cost of providing TPN, bringing the total to $3169. The incremental costs attributed to perioperative TPN were highest ($3921) for the patients least likely to benefit, that is, those who were less malnourished and at low risk of nutrition-related complications. Incremental costs were lowest ($3071) for high-risk patients. On the basis of the hospital-based method of administering TPN that was used in the clinical trial, perioperative TPN did not result in decreased costs for any subgroup of patients.