Purpose: The purpose of this study was to evaluate the association between ascending aortic diameter (AAD) as measured with low-dose chest computed tomography (LDCT) and hypertension in Korean men. Methods: Korean men (n=1,050) who were screened for lung cancer using LDCT imaging at a health promotion center in Seoul, Korea between January 1 and December 31were recruited for the study. AAD is the longest length of ascending aorta measured from approximately 15 mm above left main coronary ostium to the mid-slice level of the right pulmonary artery. Results: AAD were divided into quartiles, and the degree of hypertension was determined based on the quartiles of the AAD using logistic regression. Odds ratios (OR) for the proportion of hypertension in Q2 (1.70, 95% CI: 1.11-2.59), Q3 (2.72, 95% CI: 1.81-4.09) and Q4 (3.94, 95% CI: 2.63-5.89) were significantly greater than that of Q1 (P for trend < 0.001). Even after controlling for confounding covariates of age, BMI, total cholesterol, HDL-cholesterol, fasting glucose, GGT, ALT, eGFR, smoking status and alcohol intake, there was significant correlation. Conclusion: AAD was significantly associated with the degree of hypertension.