Macromastia causes several health problems, and reduction surgery alleviates them successfully. The purpose of this study was to investigate whether reduction mammaplasty improves possible impairments on pulmonary functions related to macromastia. Thirty-one patients participated in the study. Pulmonary function tests were performed before and 3 months after surgery with a spirometry. Preoperative and postoperative pulmonary function values were compared using a paired t test. Two patients were found to have mild restriction in preoperative spirometric analysis, and they went to normal range in postoperative analysis. All other patients were assessed as having normal values in both preoperative and postoperative analyses. Preoperative and postoperative forced vital capacity values were 2.72±0.06 and 2.79±0.05 L, respectively. The difference was statistically significant (paired t test, P=0.014). The other parameter in which breast reduction had statistically significant improvement was forced vital capacity performed/predicted ratio (paired t test, P=0.041). Additionally, the weight of resected breast tissue correlated significantly with the change of forced vital capacity (Pearson correlation coefficient=0.379, P=0.036). Breast reduction surgery improves the pulmonary function parameters that are mainly influenced by restrictive states. This result led us to consider that macromastia causes a relative restriction in chest wall compliance, and reduction of breast weight may enhance chest wall compliance and improve pulmonary function.