1.1. Oxygen saturation of capillary blood was studied in 94 full-term newborn infants. Separate determinations were made on 708 samples of blood. The infants were born vaginally by normal spontaneous or outlet forceps delivery following various forms of maternal anesthesia. Capillary blood samples were drawn at birth, one-half hour, and one hour. In some cases, samples were collected at two, three, twelve, and eighteen hours after delivery. The anesthetics studied were regional, ether with and without neonatal supplemental oxygen, nitrous oxide, cyclopropane, and Pentothal Sodium, all carefully administered for short periods.2.2. No statistically significant differences were found between the average saturations at birth or at one hour when a single anesthetic agent is compared with regional anesthesia.3.3. Significant differences were found when regional anesthesia was compared with the whole group of general anesthetics with respect to percentage of infants whose one-hour oxygen saturation was above 90 per cent.4.4. In the regional anesthesia group, 45 per cent of the infants were 90 per cent oxygen saturated, or over, at one hour of life. In the ether series three hours of life were necessary before a similar number of the infants reached 90 per cent oxygen saturation.5.5. The administration of oxygen to the newborn infant after maternal ether anesthesia produced no significant changes in oxygen saturation of the infant's blood.6.6. Artificial resuscitation, which was given if respirations were not spontaneously established within three minutes after birth, was required for none of 30 infants born of mothers receiving regional anesthesia. One of 10 infants from the Pentothal Sodium series, 3 of 10 after nitrous oxide, 14, or 45 per cent, of 31 infants from the ether series, and 7, or 54 per cent, of infants born of mothers receiving cyclopropane anesthesia required artificial resuscitation.