Background: Breast hypertrophy is seen in clinical practice to have various physical symptoms and signs on patients. These symptoms vary in severity according to breast weight. Symptoms may include back and neck pain, postural changes, skin affection (intertrigo) and psychological affection in form of depression, anxiety and low self-esteem.Insufficient and contradictory data from previous studies described the effects on chest wall dynamics, which guided this study to furtherly investigate these changes and prove the hypothesis of the relation between the resected breast weight and the improved effect on lung functions. The aim of this study is to evaluate and document this relation and hypothesis by performing pulmonary function tests pre and post operatively.Methodology and Results: Twenty-five adult female patients presenting with symptomatic macromastia were included in the study. Paired t-test showed significant change in some spirometric parameters (FVC, FVC%, B/P, FEV1, FEV1, %B/P) after reduction mammoplasty. Spearman correlation coefficient discovered a significant positive correlation between the total weight of breast tissue resected and pulmonary functions, and a non-significant correlation between the age, BMI and the pulmonary functions. Conclusion:In conclusion, this study has documented the restrictive effects on chest wall compliance caused by macromastia. Statistically significant improvement in preand post-operative pulmonary functions was documented. The correlation between the resected breast weight and pulmonary function tests improvement, proved to be linear.