Endotracheal intubation (ETI) is one of the most common emergency procedures performed in the neonatal intensive care unit (NICU).  As a convention before endotracheal intubation, the baby is either preoxygenated with 100% oxygen through bag and mask ventilation or free flow oxygen is administered during the procedure. The use of heated humidified high flow nasal cannula (HHHFNC) therapy has been tried to improve the success of endotracheal intubation in neonates. Recently it has been shown to decrease the intraprocedural physiological instability i.e., oxygen desaturation to <20% from baseline and bradycardia in neonates. To evaluate this, we plan to conduct this randomized control trial, where the study participants will be divided into two groups (HHHFNC group and free flow oxygen group) enrolling 110 intubations in each group, consisting of neonates of all gestational ages admitted in NICU who will be requiring endotracheal intubation. The primary outcome will be the successful endotracheal intubation, defined as endotracheal intubation in the first attempt not associated with oxygen desaturation to <20% from baseline and bradycardia (heart rate <100 bpm). The secondary outcome measures will include cumulative durations of oxygen desaturation <20% from baseline and bradycardia (hear rate <100 bpm), median heart rate and spo2 during the procedure and number of intubation attempts. We expect that using high flow oxygen compared to free flow oxygen during the procedure will increase endotracheal intubation success rate.