In patients with chronic obstructive pulmonary disease (COPD), early detection of noninvasive ventilation (NIV) failure is a promising technique for decreasing mortality. The objective of this study was to evaluate the efficacy of heart rate, acidosis, consciousness, oxygenation, and respiratory rate (HACOR) score in predicting NIV outcome in COPD-associated respiratory failure. A prospective observational study was conducted on 100 COPD patients with acute respiratory failure who were initiated on NIV. HACOR score was calculated at the start of NIV and after 1-2, 12, and 24 hours. NIV failure was defined as progression to invasive mechanical ventilation or death. NIV success was defined as liberation from NIV prior to hospital day seven and not meeting criteria for failure. In this study, 100 patients with COPD and respiratory failure were enrolled. Their mean age was 65.34 years [standard deviation (SD) 8.19]. Male patients were predominant (n = 81). Eighty-nine percent of patients were smokers, and the remaining had exposure to biomass fuel. At the initiation of NIV, the median HACOR score was 3 (interquartile: 2, 4). In 13% of patients, there was NIV failure. There were 17 (17%) patients whose HACOR score at initiation was ≥5. In patients with a HACOR score ≥5, the NIV failure rate was 76.4% and mortality was 41.1%. The area under the curve (AUC) for prediction of NIV failure by HACOR score at initiation was 0.980 (p-value < 0.05). The HACOR score had high sensitivity as well as specificity at initiation in the prediction of NIV failure. A higher HACOR score predicts a high chance of NIV failure. Obtaining the HACOR score at the bedside makes it convenient for assessing the efficacy of NIV in patients with COPD.