Abstract Background Neonatal acidaemia at birth can increase neonatal morbidity and mortality and it is predictive of neonatal asphyxia. The umbilical blood gas analysis is a valid tool for the evaluation of neonatal acidaemia. However, umbilical cord blood gas analysis is commonly performed in high-risk situations or in the setting of Apgar scores 7 at 5 min, arterial cord blood gas analysis showing pH 6 mmol/l. The aim was to evaluate the predictive role of blood gas analysis for respiratory distress syndrome in newborns with reassuring Apgar Score. Results 352 full term newborns were enrolled. Umbilical cord blood artery pH showed an association with respiratory distress syndrome (χ2(1) = 10,084, OR (95% CI): 3,9 × 10− 4(2,9 × 10− 6 - 0,048); p