Introduction- The reproductive system as well as other systems of the body are known to be physiologically impacted by the dynamic endocrine interplay reflecting rhythmic changes in the rate of ovarian hormone secretion during different phases of the menstrual cycle. These changes in pulmonary function occur during the various menstrual cycle phases. The aim of present study is to evaluate the pulmonary function test in females of reproductive age group around national capital region at a tertiary care center. Material & methods- At a tertiary care center, a descriptive cross-sectional study was carried out. The study involved 100 reproductive-age female with normal menstrual cycles. Measurements of pulmonary function were taken during the pre- ovulatory and post- ovulatory of the menstrual cycle. Every detail, including height in centimeters, weight in kilograms, and age, was noted, and the BMI was computed. The purpose of data analysis was to determine the statistical significance (p value) of the menstrual cycle's pre- and post-ovulatory phases. Results- Our study shows a highly significant increase in FEV1 parameter during post ovulatory phase having mean values of 2.56±0.27 as compared to pre-ovulatory phase with the mean values of 2.23±0.16. We found a significant increase in FVC (L), during post ovulatory phase as compared to pre ovulatory phase of menstrual cycle. Conclusion- FVC and FEV1 significantly increase during the postovulatory phase of the menstrual cycle, when progesterone levels are higher. Our effort to determine the correlation between the levels of the pulmonary function test at various stages of the menstrual cycle can assist clinicians in providing progesterone hormone supplementation to women suffering from inflammatory lung conditions like COPD, asthma and other lung disorders.