In nine critically ill newborns, five of them with intractable diarrhea and four surgical patients, we administered a 5% crystalline aminoacids solution (AA) and glucose in sufficient amount to provide 120 cal times kg. in 24 hours. Six of them recovered after receiving parenteral alimentation for 3 to 15 days, gained weight during or after treatment and were discharged from the hospital in good conditions. Three died, one of them presented septicemia and two pneumonia and pulmonary infarcts. The solution used generated few metabolic alterations, the acid-base status remained within normal range and there were not important changes in the sodium and potassium serum concentrations. On the contrary, children with hyponatremia and hypokalemia at the beginning of the treatment, normalized these constants within the first hours, as diarrhea ceased. The most frequent complications were infiltrations and reaction of the surrounding tissue of the catheterized vein and local skin infection. Only one patient died of septicemia, possibly caused by this proceeding. In summary, parenteral alimentation though not free from risk, seems to be a useful proceeding when oral feeding is impossible or inadvisable. The utmost danger is septicemia. Metabolic changes are minimal and they do not mean a risk for child's life; nevertheless, there is a need for long term studies to bring up definite conclusions. The solutions in actual use are probably not the most physiological for the newborn. It is necessary to adequate them according to the new advances made on child nourishment during his first days of life.