Purpose: to compare pulmonary morphology between fighter pilots and nonflying personnel using low-dose chest CT (LDCT) quantification. Methods: A total of 36 military fighter pilots and 36 nonflying personnel who were non-smoker in our institute from April to July 2013 were included in our study. The LDCT images were reviewed and the prevalence of each LDCT finding was compared by univariate analysis. The diameters of the pulmonary artery (PA) and the ascending aorta (AA) were measured and the PA: AA ratio were calculated and they were compared between the military fighter pilots and nonflying personnel. Quantification with LDCT images using in-house software based on the fullwidth- half-maximum method was performed. Lung volume, emphysema index, mean lung density, airway diameter and airway luminal area of subsegmental bronchus were also obtained and compared between the two groups using paired-t-test. Results: There was no statistically significant difference in the prevalence of LDCT findings between the two groups. AA, PA, and PA:AA ratio of the subjects did not show any statistically significant difference between the two groups. The mean airway diameter (mm) and airway luminal area (mm2) were significantly larger than that of the nonflying personnel (3.50 0.34 vs 3.21 0.44 and 11.29 2.84 vs 9.26 2.93, respectively) but lung volume, emphysema index, and mean lung density were not significantly different between the two groups. Conclusion: The occupational exposure to fighter flight might have influence on the lung, especially, airway dilatation.