A bstract Severe hypoxemic respiratory failure is frequently managed with invasive mechanical ventilation with or without prone position (PP). We describe 13 cases of nonhypercapnic acute hypoxemic respiratory failure (AHRF) of varied etiology, who were treated successfully in PP without the need for intubation. Noninvasive ventilation (NIV), high-flow oxygen via nasal cannula, supplementary oxygen with venturi face mask, or nasal cannula were used variedly in these patients. Mechanical ventilatory support is offered to patients with AHRF when other methods, such as NIV and oxygen via high-flow nasal cannula, fail. Invasive mechanical ventilation is fraught with complications which could be immediate, ranging from worsening of hypoxemia, worsening hemodynamics, loss of airway, and even death. Late complications could be ventilator-associated pneumonia, biotrauma, tracheal stenosis, etc. Prone position is known to improve oxygenation and outcome in adult respiratory distress syndrome. We postulated that positioning an unintubated patient with AHRF in PP will improve oxygenation and avoid the need for invasive mechanical ventilation and thereby its complications. Here, we describe a series of 13 patients with hypoxemic respiratory of varied etiology, who were successfully treated in the PP without endotracheal intubation. Two patients (15.4%) had mild, nine (69.2%) had moderate, and two (15.4%) had severe hypoxemia. Oxygenation as assessed by PaO 2 /FiO 2 ratio in supine position was 154 ± 52, which improved to 328 ± 65 after PP. Alveolar to arterial (A-a) O 2 gradient improved from a median of 170.5 mm Hg interquartile range (IQR) (127.8, 309.7) in supine position to 49.1 mm Hg IQR (45.0, 56.6) after PP. This improvement in oxygenation took a median of 46 hours, IQR (24, 109). Thus, voluntary PP maneuver improved oxygenation and avoided endotracheal intubation in a select group of patients with hypoxemic respiratory failure. This maneuver may be relevant in the ongoing novel coronavirus disease pandemic by potentially reducing endotracheal intubation and the need for ventilator and therefore better utilization of critical care services. How to cite this article Rao SV, Udhayachandar R, Rao VB, Raju NA, Nesaraj JJJ, Kandasamy S, et al. Voluntary Prone Position for Acute Hypoxemic Respiratory Failure in Unintubated Patients. Indian J Crit Care Med 2020;24(7):557–562.