Background High-flow nasal cannula therapy (HFNC) is an non-invasive ventilation (NIV) mode of respiratory support, that allows for delivering heated and fully humidified gas with a fraction of inspiratory oxygen (FiO2) ranging between 21% and 100%, matching or even exceeding the patients’ inspiratory demand to achieve oxygen therapy, apnoeic oxygenation and ventilation. Objective The objective of our study was to review the application of HFNC during perioperative period, as well as the use of HFNC in children with respiratory insufficiency of different aetiologies. Content The emerging evidence from studies suggests that the use of HFNC therapy may be associated with reduced work of breathing, improved ventilation efficiency and a decreased need for intubation in children with respiratory Insufficiency. In addition, HFNC therapy has been proposed to limit oxygen desaturation by prolonging apnoeic oxygenation during induction of anaesthesia and intubation. HFNC therapy may also be valuable in oxygen administration during invasive procedures. We review the proposed mechanisms of actions, indications, advantages and complications of HFNC therapy in children. Trend HFNC remains a new technique which has not been fully characterized, but holds great promise. Future research is required to test its indications and to examine the safety and effectiveness in children.