An improved system for preparing total parenteral nutrient (TPN) solutions is described. The new system uses a personal computer, a three-station volumetric pump, and empty polyvinyl chloride (PVC) containers. The computer's order-entry screen facilitates data entry by displaying a format similar to the physician's order sheet. After calculating the volumes of i.v. solutions and additives and the total cost of the TPN solution, the computer prints labels containing this information. Using the volumetric pump, the required volumes of crystalline amino acids, dextrose injection, and sterile water for injection are added simultaneously to either one-liter or three-liter PVC containers. Each bag contains the patient's entire daily TPN requirements. Approximately 30 liters of TPN solution are prepared daily by specially trained technicians in a centralized i.v. room. Compared with the previous method of preparing TPN solutions using evacuated one-liter glass bottles, the average time required to prepare and determine the cost of each patient's TPN solutions has decreased from 35 to 21 minutes daily. Total savings resulting from reduced materials and labor costs is approximately $28,240 annually. The new system for preparing TPN solutions is efficient and cost effective.