The effects of total parenteral nutrition were studied in two anuric neonates and an anuric infant. Based on the observations of urea production, nitrogen balance, and serum osmolality, the bulk of the infused nitrogen appeared to be incorporated into the body proteins. The need for potassium, calcium, phosphorous, and magnesium substitution was also indicative of net anabolism. Despite effective utilization of the amino acids, high plasma levels of phenylalanine and methionine, and extremely low levels of the urea cycle intermediates were measured. We conclude that the application of carefully planned parenteral nutrition may aid in the management of newborns with failing kidneys and that it influences considerably the indications of dialysis in early infancy.