Background: Acute respiratory failure (ARF) is a major cause of intensive care unit (ICU) admission and is associated with significant morbidity and mortality. Non-invasive ventilation (NIV) has become an effective alternative to invasive mechanical ventilation in appropriately selected patients, reducing complications associated with endotracheal intubation.Objective: To evaluate the clinical outcomes of non-invasive ventilation in patients with acute respiratory failure and identify factors associated with NIV success and failure.Methods: A retrospective observational study was conducted among 280 adult patients with acute respiratory failure managed with NIV in a tertiary care hospital between January and December 2025. Demographic characteristics, underlying diagnosis, arterial blood gas parameters, duration of NIV, complications, need for intubation, ICU stay, and mortality were analyzed.Results: NIV was successful in 211 patients (75.4%), while 69 patients (24.6%) required invasive mechanical ventilation. Overall mortality was 13.2%. Chronic obstructive pulmonary disease (COPD) exacerbation demonstrated the highest NIV success rate. Predictors of NIV failure included severe hypoxemia, high APACHE II score, delayed NIV initiation, persistent respiratory acidosis, hemodynamic instability, and multiorgan dysfunction.Conclusion: Non-invasive ventilation is an effective treatment modality for carefully selected patients with acute respiratory failure. Early initiation and appropriate patient selection significantly improve clinical outcomes while reducing intubation rates and ICU mortality.