Both hypoxemic and hypercapnic respiratory failure occur in patients with progressive chronic obstructive pulmonary disease (COPD). The presence of respiratory failure predicts worse prognosis and higher mortality. Supplemental oxygen therapy (SOT) and noninvasive ventilation (NIV) have been increasingly used to treat these abnormalities, aiming to improve both prognosis and quality of life. This review provides an overview of the evidence and current recommendations for the use of SOT and NIV in COPD.