Pursed lips breathing (PLB) training is often used in the management of patients with chronic obstructive lung disease (COLD). Previous clinical studies have demonstrated that PLB improves arterial oxygen saturation (SaO2) and CO2 removal as well as relieving dyspnea. Twelve hypoxemic subjects with stable COLD were randomly assigned to either the pursed lips (P) or control group consisting of general relaxation (R). The SaO2 was monitored via ear oximetry, and respiratory rate and tidal volume were monitored using a strain gage transducer and the minute volume was calculated. The PLB was taught by an experienced instructor using the ear oximeter as a monitoring display with a goal toward increasing SaO2. The subject was taught general relaxation (Rlx) with the aid of pleasant music. We compared PLB and Rlx treatments using an A-B-A crossover study design. In both groups, PLB significantly improved SaO2 over baseline (p less than 0.001) whereas Rlx did not. We conclude that patients can learn to increase their SaO2 by PLB using ear oximetry adjunctively.