Purpose: The purpose of this study was to determine the effects of chest resistance exercise on Forced Expiratory Volume per second and on fatigue in patients with chronic obstructive pulmonary disease (COPD). Methods: In all, 62 male patients with COPD were included in this study. The experimental group included 32 patients who were treated with chest resistance exercise using the PNF technique with medication. The control group included 30 patients who were treated only with medication. Subjects were stratified into the 2 groups by randomized clinical sampling. Before the start of the experiment, forced expiratory volume at the first second (FEV1) and lactic acid were tested in both experimental and control groups. The experimental group did chest resistance exercise for 6 weeks, 4 times per week, 30 min per day, and the effects of this exercise in patients with COPD was determined by comparing the results of FEV1 and lactic acid tests before and after the experiment between and within the experimental and control groups. Results: There was a statistically significant within group difference for FEV1 MEAS and FEV1 %PRED. There was statistically significant control group of FEV1 MEAS and FEV1 %PRED There was a statistically significant difference in the experimental group for fatigue, comparing scores before and after the test. There was a statistically significant control group of fatigue, in comparison of between the groups of FEV1 MEAS, FEV1 %PRED, fatigue(p<0.01)(p<0.05). Conclusion: More research on COPD will be necessary for improving pulmonary function and reducing fatigue. Further studies on COPD will be required for improving pulmonary function and reducing of fatigue.