The condition of each newborn infant was expressed by a score, the sum of five numbers obtained within 60 seconds after complete birth. The numbers were determined by objective observations of heart rate, promptness and vigor of the first respiratory efforts, and reflex response to certain stimuli, muscle tone, and color. The highest possible score was 10, representing the optimum condition of the infant. The predictive value of such scores is here established by a study of the scores of 15,348 infants, for the death rate among infants scoring 2, 1, or 0 was 15%, while that for infants scoring 10 was 0.13%. The score was found to be a measure of the relative handicaps suffered by infants born prematurely, delivered spontaneously at term, delivered by cesarean section, or subjected to other obstetrical and anesthetic hazards. The lower scores were generally associated with chemical findings characteristic of asphyxia in the blood obtained by umbilical catheterization. The score was especially useful in judging the need for resuscitative measures, such as respiratory assistance.