Background: When breathing is compromised and the amount of carbon dioxide exhaled by the respiratory system is less than the amount of carbon dioxide produced by the tissues, hypercapnia and respiratory acidosis result.The present study was conducted to assess serum electrolytes, acid–base balance and need for non-invasive ventilation in patients with hypercapnic acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods: 82 patients with (AECOPD) of both genders were selected. Blood investigations such as arterial blood gases (ABG), electrolyte levels (Sodium (Na) and potassium (K) were performed. NIV was performed through oronasal mask with a pressure/ volume ventilator. Support pressure, positive end expiratory pressure (PEEP) was used. Results: Out of 50 cases of compensated respiratory acidosis, 10 were NIV positive and 40 were NIV negative. Out of 18 cases with mixed respiratory acidosis and metabolic alkalosis, 15 were NIV positive and 3 were NIV negative. Out of 14 cases with combined respiratory and metabolic acidosis, 12 were NIV positive and 2 were NIV negative. The difference was significant (P< 0.05). The mean sodium level was 135.2 mEq/l and 137.4 mEq/l, potassium level was 4.9 mEq/l and 3.2 mEq/l and bicarbonate level was 29.5 mEq/l and 23.7 mEq/l in NIV positive and NIV negative patients. The difference was significant (P< 0.05). Improvement was seen in 17 cases of compensated respiratory acidosis, 11 cases of mixed respiratory acidosis and metabolic alkalosis and 5 cases of combined respiratory and metabolic acidosis. The difference was significant (P< 0.05). Conclusion: While minor AECOPD episodes are usually curable, more severe respiratory failures are linked to a significant death rate and a protracted period of impairment for those who survive.