ContextExisting medications for chronic obstructive pulmonary disease (COPD) do not modify the long-term decline in lung functions. The increasing prevalence of COPD requires the development of interventions beyond the usual medical treatment, with a specific focus on rehabilitation. Controlled breathing (pranayam) is a specific set of respiratory exercises within yoga that has been shown to improve the resting respiratory rate, vital capacity, maximum voluntary ventilation, breath-holding time, and maximal inspiratory and expiratory pressures. Objective In this study, pranayam was analyzed as an adjunct treatment for medically stable individuals with moderate to severe COPD. Design The research team carried out a case control study. Setting This study took place at a tertiary care institution, with the participation of the departments of Physiology, Yoga and Naturopathy, and Pulmonary Medicine at Pandit Bhagwat Dayal Sharma Postgraduate Institute of Medical Sciences in Rohtak, Haryana, India. Participants Participants were 50 medically stable individuals with moderate to severe COPD. Intervention Twenty-five participants in the intervention arm (IA) were trained to practice pranayam for 30 min 2 ×/d and also received the usual medical treatment. The control group also included 25 participants, and they received the usual medical treatment only, without pranayam. Outcome Measures The COPD assessment test (CAT) score and the body-mass index, obstruction, dyspnea, exercise (BODE) capacity index were assessed at baseline and at 3 mo. The results were expressed using standard statistical methods. Results For the IA, a significant improvement occurred in the CAT score (21.2 ± 2.6–17.4 ± 2.5, P < .001) and in the impact level, which moved from high (>20) to medium (10–20) after 3 mo of practicing pranayam. The control arm (CA) showed no significant improvement in the CAT score (21.6 ± 2.7–21.4 ± 2.7). Although the IA showed a significant improvement in a 6-min walk test (6MWT) when compared to the CA, (1) the IA’s forced expiratory volume in 1 sec (FEV1), which is a measure of airflow that is commonly impaired in COPD patients and which is associated with poor functional status, showed no significant improvements, and (2) the IA’s BODE capacity index showed no significant improvements. Conclusion The current study shows that pranayam has been demonstrated as useful for individuals with moderate to severe COPD. Significant improvements in the IA’s CAT scores after 3 mo of practice suggests that pranayam can improve the subjective experience of health, disease severity, and functional status for COPD patients, without much improvement in FEV1 actually occurring and with airflow limitation not fully reversible but usually progressive. The research team concluded that pranayam is a useful adjunct treatment and can be an effective rehabilitation program for individuals with COPD.