Background: The preterm survival is increased by mechanical ventilation but its prolonged unnecessary utilization results in certain complications. Therefore, if the infant is “ready for extubation," extubation should be performed immediately. However, a failed extubation during reintubation attempts may also cause complications. There are no standard recommendations and predictors for the safe extubation of preterm neonates at present.Objective: The aim of the current study was to evaluate respiratory severity scores (tidal volume paco2, O2 saturation) for prediction of extubation failure. Patients and methods: A prospective cohort study was conducted on 40 preterm mechanically ventilated infants in Neonatal Intensive Care Unit (NICU), Faculty of Medicine, Zagazig University Children Hospitals. All recruited preterm infants were of <35 weeks gestational age and were ready for extubation. All patients underwent measurement of arterial blood gases respiratory parameters. Results: After using ROC curve, oxygenation index, RSS, RSS/kg and PO₂ were found to be good predictors for failed extubation. Conclusion: In pre-term infant, O₂ saturation, Paco₂, Tidal volume, Respiratory severity score showed high sensitivity and specificity for extubation failure prediction.