Preoperative chemoradiation therapy (CRT) has been considered as an effective treatment for non-small cell lung cancer. However, there is concern that CRT progresses atherosclerosis in cancer survivors. This study sought to determine if preoperative CRT exacerbated thoracic aortic calcification (TAC) detected by computed tomography (CT) in patients with lung cancer. Among 473 patients who underwent surgery for lung cancer at Okayama University Hospital between 2011 and 2015, 34 patients undergoing preoperative CRT and surgery (CRT group) and 33 matched patients undergoing initial surgery (non-CRT group) were analyzed and compared. The volume of TAC between the 2nd and 12th thoracic vertebrae was quantitatively measured by CT at baseline and 1-year follow-up. Patients in the CRT group (62 ± 7 years old, 74% male) received cisplatin chemotherapy with docetaxel or vinorelbine and radiation therapy (mean 47.3 ± 4.0 Gy). The percent change in TAC volume was significantly greater in the CRT compared with the non-CRT group (58.7%, 95% confidence interval [CI] 41.7-75.7% vs. 27.2%, 95% CI 9.9-44.4%; p = 0.01). Multivariate logistic regression analysis identified CRT as an independent factor associated with greater TAC progression (> the median value) (odds ratio 3.63, 95% CI 1.19-11.08; p = 0.02). In conclusion, preoperative CRT for lung cancer exacerbates TAC. Follow-up of such patients should thus include careful longitudinal assessment for cardiovascular disease.