Five surgical infants, ages 3 to 30 days, were studied while receiving peripheral total parenteral nutrition for a period of 2 weeks. By a randomized sequence, either 10 or 20% safflower oil emulsion was infused the first week, followed by the alternate solution during the second week. Caloric intake was 80 to 100 cal/kg/day, of which lipids comprised one-third to one-half. No adverse side effects were noted. Eosinophilia developed in three patients, but otherwise no changes in hematologic and biochemical parameters, including liver enzymes, were noted. Weight gain averaged 11.1 g/kg/day during the study period and was similar for the 10 and 20% solutions. Intravenous fluid intake averaged 21 ml/kg/day less during the week of the patients received 20% fluid emulsions. The 20% safflower oil emulsion proved comparable to the 10% solution in both safety and efficacy and enabled significant reduction of fluid intake while maintaining infused caloric levels.