Introduction: The high-flow nasal cannula (HFNC) is a novel device used for giving O2 at high flows. HFNC delivers heated humidified oxygen up to 37°C at high flows of 60 L/min at an adjustable fraction of inspired oxygen (FIO2) of 0.21 (room air) to 1.0 (100% oxygen) through a nasal cannula. HFNC is utilized as an alternative mode of oxygen supplementation in hospitals. In light of the coronavirus disease 2019 (COVID-19) a global pandemic, HFNC was widely used in patients for airway management in managing patients with respiratory distress. It improves mucociliary clearance and helps in the maintenance of immune function of mucosal surfaces. HFNC humidifies the oxygen before delivering it to the patient, similar to the normal physiology of breathing. Humidification reduces airway resistance, improves mucociliary clearance, and protects the airway mucosa. HFNC helps in loosening respiratory secretions and thus aids in expelling them easily. It also reduces the incidence of mucus plug formation and atelectasis. The use of HFNC for the management of COVID-19 has been explored and has increasingly become an important strategy for preventing intubation and mechanical ventilation. Conclusion: High flow nasal cannula is a novel device used for providing oxygen at high flows. The use of HFNC for adult patients across different clinical settings is increased since few years. With the evidence suggested by studies, HFNC may be considered as an alternative mode of delivering oxygen between conventional oxygen therapy and NIV. In rising cases of covid 19 and oxygen demand, HFNC was considered as the best choice for delivering oxygen to a patient who has respiratory distress.