The upper and lower airways are typically subjected to identical inflammatory stimuli and comprise a single organ that is functionally connected. 40 patients with chronic rhinosinusitis with nasal polyps who had failed medical treatment and undergone FESS participated in our study. Prior to surgery and three months after surgery, nasal obstruction symptoms were measured using the NOSE score system and pulmonary function tests were evaluated using spirometry. The mean Nose Score was 70 before surgery but dropped to 4 afterward, with a p value < 0.001 showing a statistically significant improvement in the nasal symptoms following FESS. The mean pre-operative FVC, FEV1, and FEV1/FVC% values were 3.19, 2.53, and 78.81%, respectively, while the mean post-operative values were 3.14, 2.5, and 79.01%. Following FESS, there wasn't a statistically significant change in lung function tests. Our study showed that percentage of change of total NOSE score has a statistically significant Negative correlation with percentage of change of pulmonary function tests parameters. This study demonstrates the positive effects of FESS on nasal polyposis patients' quality of life and nasal obstruction symptoms without having any negative impacts on the lower airways. [ABSTRACT FROM AUTHOR]