Considerable effort should be made to optimise parenteral nutrition of preterm infants in order to limit the development of postnatal growth restriction. A monocentric before-and-after study design was used to determine the effects of computerising parenteral nutrition ordering on the composition of parenteral nutrition (PN) solutions and early clinical outcomes of preterm infants born < or =28 weeks of gestation. Parenteral protein intake during the first week of life and parenteral lipid, glucose and energy intakes during the first and second week of life were significantly higher in infants assessed after the introduction of computerised parenteral nutrition ordering. This led to a significant reduction in the cumulative energy deficit over the first 28 days of life and to an improvement in both early growth and pulmonary outcome. Computerising the PN ordering process improves the nutrient content of the PN solutions and early postnatal outcome.