COPD is a common and a progressive disorder that is characterised by respiratory symptoms and airflow limitation due to the abnormalities of the airway or alveoli. Proprioceptive neuromuscular facilitation technique can increase the contractive capacity of muscles. The study aimed at assessing the effect of Proprioceptive neuromuscular facilitation stretch of pectoralis major muscle on chest expansion and pulmonary function values in COPD patients. Methods: hold relax PNF of pectoralis major muscle was given for a duration of 6 weeks on the particpants who are met with inclusion and exclusion criteria. Chest expansion was measured at axillary level and xiphisternal level, FEV1, FVC and FEV1/FVC were measured pre and the post intervention. Results: statistical analysis was done using paired t test (p<0.05). the results of  the study shows that there is increase in the chest expansion at axillary level and xiphisternal level and increase in the FEV1/FVC  ratio following 6 weeks of hold relax PNF stretch of pectoralis  major in COPD patients. Conclusion: the study concludes that with hold relax PNF stretch there is increase in chest expansion and pulmonary function values.