1. The present study conducted on paediatric patients shows that ultrasonography offers a better alternative than the frequently used age-based formula while selecting an appropriate sized uncuffed endotracheal tube which would provide optimal fit and ventilation. 2. Better prediction of endotracheal tube size is associated with limited number of laryngoscopies and tube changes which reduces the incidence of trauma to the upper airway. 3. Ultrasound assisted assessment of subglottic diameter is easy to learn and apply and they can be performed at the bedside whenever required. 4. Ultrasound should be used whenever possible for choosing the uncuffed endotracheal tube in paediatric population. 5. There is a need to expand the utility of Ultrasound in assessing subglottic diameter in Indian population and in children below 1 year for further validation and enhancement of the rate of agreement further.