In order to determine the normal values of arterial blood gases in the umbilical artery of term infants at 3400 m altitude, a cross-sectional study was conducted. It was performed in the umbilical artery blood of 300 term infants, with an adequate gestational age and whose birth took place between January 2010 and December 2011 at the Essalud National Hospital Adolfo Guevara Velazco (Cusco, Peru). It was found that the average pH of healthy term infants was 7.33 ± 0.07; the values for percentiles 5 and 95 were 7.18 and 7.40 respectively. Tables with the 5th and 95th percentiles for pH, pO2, pCO2, SO2, p50, base excess and HCO3 of the umbilical artery of term infants at 3400 m altitude are provided.