Eighteen pre and/or postoperative patients underwent TIN using either fat or carbohydrate as a caloric substrate source for a similar period. Positive nitrogen balance was achieved with either solution for an equal number of days when balance studies were complete. Both groups demonstrated weight gain but it was more marked in the carbohydrate TIN group. One patient in the carbohydrate TIN group was changed to Intralipid because of a catheter related complication. This patient continued to show positive nitrogen balance while on Intralipid. There were 4 deaths in the 18 patients unrelated to TIN. It is concluded that Intralipid, when given through a peripheral vein with a nitrogen source, can produce positive nitrogen balance and is a safe and effective means for doing this. Images Fig. 1.