This study was designed in a tertiary health centre in south-eastern Turkey to compare the effectiveness of non-invasive ventilation (NIV) plus standard medical therapy (ST) to ST alone, in acute hypercapnic respiratory failure (AHRF) due to chronic obstructive pulmonary disease (COPD) exacerbation. Thirty-four consecutive patients were randomly assigned to receive either NIV plus ST or ST alone. NIV was applied with a simple non-invasive ventilator through a full face mask in the general ward. Initial settings for inspiratory and expiratory positive airway pressures were 9 cm HO2, and 3 cm HO2, respectively. We observed statistically significant improvements in the first hour of NIV regarding respiratory rate (p<0.001), pH (p<0.05), PaO2 (p<0.05), and PaCO2 (p<0.001). PaO2 (p<0.05) showed significant improvement only in the first hour of ST. The intubation rate and duration of hospitalisation in the NIV group were significantly shorter than those in the ST group (p<0.05). We conclude that NIV provides adjunctive therapeutic benefits compared with ST alone, and should be the choice of first step treatment in the AHRF due to COPD exacerbation in the appropriate setting and in selected patients.