BACKGROUND: Computed tomography angiography (CTA) is routinely used to diagnose thoracic aortic pathology and for surveillance after thoracic endovascular aortic repair. The purpose of our study was to assess the prevalence of unsuspected disease identified on CTA examination for thoracic aortic pathology and to determine potential clinical significance of these findings. METHODS: A retrospective review of 242 patients (136 men and 106 women; mean age, 65.7 ± 13.9 years) referred for clinical evaluation of thoracic aortic pathology during a 12-year period was performed. CTA was acquired after obtaining full written informed consent and injecting nonionic contrast Omnipaque 350 intravenously. Subsequently, axial images were obtained from the thoracic inlet through the pubic symphysis. The prevalence of incidental findings was recorded. A finding was judged potentially significant if a therapeutic intervention or radiologic follow-up was deemed advisable on the basis of the CTA findings. RESULTS: Prevalence of incidental findings were noncalcified pulmonary lesions (subcentimeter nodule [28, 11.57%], nodule >1 cm [16, 6.61%], and pulmonary mass >3 cm [4, 1.65%]), calcified pulmonary nodules (35, 14.46%), simple liver cysts (32, 13.22%), contrast-enhancing liver lesion (7, 2.89%), renal mass (7, 2.89%), and pancreatic mass (5, 2.06%). Subsequent diagnostic tests were recommended for 63 findings in 55 (22.72%) patients, which revealed 11 (4.5%) patients had metastatic disease-six primary lung cancer, one metastatic lesion (mets) to the lung, one renal cell carcinoma with mets in the lung, one primary pancreatic adenocarcinoma with mets in the liver, one unknown primary with mets in the liver, and one other poorly differential metastatic carcinoma with lesions in the pancreas, adrenal glands, kidneys, and small bowel with unknown primary. CONCLUSION: CTA evaluation in patient with aortic pathology may reveal a high rate of malignant lesions. Attention to the incidental finding of suspicious lesion on computed tomographic scans in the chest and abdomen and appropriate follow-up by the requesting surgeon is important in patients undergoing surveillance for aortic pathologies.