Background and Objectives: Nasal surgery is known to improve the quality of life in patients with obstructive sleep apnea; however, its effect on the airway structure is little known. This study attempted to identify the impact of nasal surgery on the pharyngeal airway structure.Subjects and Method We enrolled in the study patients who underwent nasal surgery from July 2015 to March 2018 due to nasal obstruction with severe snoring or sleep apnea. Patients with palate surgery or previous history of airway surgery were excluded. Demographic factors, symptoms regarding nasal obstruction, sleep study, preoperative cephalometry, and postoperative 3-month cephalometry were taken into account and analyzed. We also performed a subgroup analysis according to the severity of sleep apnea. Results: Sixty-three patients were enrolled in this study. Soft palate thickness showed no significant change. Pre and postoperative soft palate thickness were 10.82±3.00 and 11.11±3.35 (p=0.261), respectively. However, the pharyngeal airway space was enlarged via nasal surgery from 12.05±3.35 to 13.04±3.35 (p=0.006), respectively. The subgroup analysis showed that the pharyngeal airway was mainly enlarged in the patients with lower Apnea-Hypopnea Index (AHI). Conclusion Although nasal surgery does not reduce soft palate thickness, it can enlarge the pharyngeal airway space. The effect of surgery would be more prominent in patients with AHI of lower than 15 event/hour (p=0.005) as nasal surgery alone does not affect the pharyngeal airway of patients with AHI greater than 15.