Introduction: Chronic Obstructive Pulmonary Disease (COPD) impairs patients` quality of life and clinical outcomes. Pulmonary rehabilitation (PR) program can improve the functional capacity in patients with chronic lung disease. Thus, the study aimed to evaluate the effect of the PR program on the quality of life, anxiety, depression, and pulmonary function of patients with COPD. Materials and Methods: In this single-group before-and-after clinical trial, adult patients with COPD and recent history of exacerbation were recruited. The intervention was a PR program, including training of breathing exercises at home and aerobic exercise program, twice a week about 30 to 60 min for 8 weeks. The program was prepared according to the patient’s tolerance by a sports medicine specialist in a pulmonary rehabilitation clinic. The primary outcome was quality of life measured by the St. George’s Respiratory Questionnaire (SGRQ). Secondary outcomes were assessing anxiety, depression, pulmonary function, COPD status, the ability to walk, and shortness of breathing. All outcomes were measured before and one week after the program. Results: Twenty-two eligible patients of both genders (68% male and 32% female) with a Mean±SD age of 65.09±9.72 years finished the program. Quality of life was improved significantly following the intervention (51.49 [16.68] vs 4275 [15.63]; P<0.001]. Anxiety and depression (P<0.001), pulmonary function parameters, such as forced expiratory volume in 1 second (FEV1) (P<0.001) and FEV1/ forced vital capacity (FVC) ratio (P=0.015), COPD status (P=0.001), the ability of walk1ing (P<0.05), and shortness of breath (P=0.001) were improved significantly after the intervention. Conclusion: The PR program resulted in clinical improvement in patients with COPD. Thus, we recommend that it be used besides medical management.