Introduction: Non-invasive ventilation (NIV) refers to the provision of ventilator support through the patient’s upper airway using a mask or similar device1. NIV reduces the need for endotracheal intubation and improves survival. There is no hundred percent success rate with the aid of NIV for managing respiratory failure. There are instances in which management may have to be changed to intubation and invasive mode of mechanical ventilation. Some patients will hold on to NIV for initial period and may ultimately may go for endotracheal intubation. It is important to ascertain the factors associated with NIV failure so that we can identify the high-risk subset of patients who are likely to fail a trial of NIV, to prevent unnecessary mortality. Objectives • To determine the association between NIV outcome and age. • To determine the association between NIV outcome and history of previous mechanical ventilator-management among patients. Methods 80 adult patients diagnosed with Type 2 respiratory failure were included in this study, on a long observational study basis. Demographic history, physical examination and relevant investigations for type 2 respiratory failure were noted, and NIV-pressure support mode (PSV) were initiated on all patients. Ventilator was equipped with adjustable pressure limits and patients were ventilated as per the predefined inspiratory and expiratory airway pressure settings with each inspiration being triggered by patient’s spontaneous breath. The interface used during the study was a well-fitting Oro-nasal mask. Subsequent adjustments were carried out according to the need of the patient and the results of blood gas analysis. All patients were given oxygen and titrated during ventilation to maintain oxygen saturation between 88%-92%. Serial ABG monitoring was done at the end of 1-2-hour, 4-6 hour and any other time if patient’s condition required so. Any deterioration of pH (pH<7.25) and increase PaCO2, worsening of mental status (Glasgow coma scale <8), hemodynamic instability, intolerance to NIV, all such patients were proceeded for endotracheal intubation and invasive mechanical ventilation.Results: No association was found between age and successful NIV outcome in this study p=0.974 (Chi-square test), whereas it was noted that patients who had a previous history of undergoing mechanical ventilation had poor outcome compared to those who hadn’t P=0.002 (Fisher’s exact test).Conclusion: From the present study it was evident that successful NIV outcome has no association with age of the patient whereas a previous history of mechanical ventilation support has a poor outcome with NIV support.