Background: Chronic Obstructive Pulmonary Disease (COPD for short) occurs when permanent blockages form within the pulmonary system that interfere with the transfer of vital gasses. There are two underlying disorders that can cause COPD: Emphysema and chronic Bronchitis. Incentive spirometer is a type of bronchial hygiene therapy. This helps to increase the inhaled lung volume, improve in get rid of mucus or secretions and to avoid serious lung infections in COPD patients. Objectives: (1) To assess the level of dyspnea and pulmonary functions before and after the use of incentive spirometer among COPD patients. (2) To evaluate the effectiveness of incentive spirometer between experimental and control group. (3) To findout the association between selected demographic variables and the levels of dyspnea and pulmonary functions in the experimental group after using incentive spirometer. Materials and Methods: Quasi–experimental Pretest – Post-test Control Group design were used. Non-probability purposive sampling technique used. The sample size for this study was fourty COPD patients out of which 20 patients were considered as Control group and another 20 patients as Experimental group. Results: The obtained Paired ‘t’ test value for the experimental group is 21.5 was markedly significant at p < 0.01 level whereas in the control group there was no significant difference found (t = 1.94, p = 0.06) and also there is significant difference noted in the pulmonary parameters (p = 0.01) between experimental and control group after using incentive spirometer. Conclusion: The study proved that incentive spirometer is effective in improving pulmonary functions of COPD patients.