The aim of this study was to establish the reference values of preductal oxygen saturation (SpO(2)) in healthy infants immediately after birth. SpO(2) recordings of 200 term neonates (vaginal group;n=150 and cesarean group;n=50) with regular respiratory pattern were evaluated. The median SpO(2) values in the first, fifth and tenth minutes were 71, 92, and 98% in vaginal deliveries and 70, 79, and 96% in cesarean deliveries, respectively. SpO(2) was significantly lower in the cesarean group at any time after the first minute of life (p < 0.0001). The time needed to reach a SpO(2)> 90% was three times longer in cesarean deliveries. Healthy neonates are poorly saturated immediately after birth. The duration to reach a SpO(2)> 90% was longer in infants born by cesarean deliveries.