Purpose: This study examined whether breathing exercises might increase the chest expansion and pulmonary function of stroke patients. Methods: Twenty four patients with stroke were assigned randomly into two groups: a combination of diaphragmatic resistive breathing and pursed-lip breathing exercise (CB) group (n=10) and control group (n=14). The CB group completed a 4-week program of diaphragmatic resistive breathing and pursed-lip breathing exercise. The subjects were assessed using the pre-test and post-test measurements of the chest expansion (length for resting, deep inspiration, deep expiration, deep expiration-inspiration) and pulmonary function (forced vital capacity (FVC), forced expiratory volume at one second (FEV1), FEV1/FVC, peak expiratory flow (PEF), vital capacity (VC), tidal volume (TV), expiratory reserve volume (ERV), inspiratory reserve volume (IRV)). Results: A comparison of the chest expansion between the pre and post tests revealed similar rest, deep inspiration, deep expiration, and deep expiration-inspiration lengths in the CB and control groups (p>0.05). A comparison of the pulmonary function between pre and post tests, revealed significant improvements in the FVC, FEV, PEF, VC, IRV, and ERV in the CB group (p<0.05). There was a significant difference in the FVC, FEV1, PEF, VC and IRV between the 2 groups (p<0.05). Conclusion: These findings suggest that breathing exercise should help improve the pulmonary function, such as the volume and capacity. This suggests that the pulmonary functions of stroke patients might be improved further by a continued respiratory exercise program.