There are limited data regarding the role of coronary computed tomographic angiography (CCTA) in asymptomatic patients with type 2 diabetes mellitus. We analyzed 557 asymptomatic type 2 diabetic patients who underwent CCTA. Cardiac event was defined as a composite of cardiac death, nonfatal myocardial infarction, acute coronary syndrome requiring hospitalization, or late revascularization. Atherosclerotic plaques were observed in 395 patients (70.9%), and 170 patients (30.5%) showed significant coronary artery disease (CAD) on CCTA. Ninety-two patients (16.5%) were associated with a significant stenosis in the left main or proximal left anterior descending artery. During the follow-up period (33.7 ± 7.8 months), although an excellent prognosis was observed in patients without significant CAD on CCTA, those with significant CAD showed more cardiac events (7.1% vs 0.5%) and lower 3-year event-free survival rates (99.2 ± 0.6% vs 90.9 ± 2.6%, p <0.001). Furthermore, in group with significant CAD, patients with significant CAD in the left main or proximal left anterior descending artery had more cardiac events (10.9% vs 2.6%) and lower 3-year event-free survival rates (97.4 ± 1.8% vs 86.1 ± 4.2%, p = 0.049). On multivariate analysis, family history of premature CAD, previous history of stroke, higher UK Prospective Diabetes Study 10-year risk scores, neuropathy, and retinopathy were independent clinical predictors of having significant CAD and left main or proximal left anterior descending artery significant CAD on CCTA. In conclusion, about 1/3 of asymptomatic type 2 diabetic patients had significant CAD on CCTA with a subsequent high risk for cardiac events. These findings suggest that CCTA may have a potential role in identifying patients with high cardiovascular risks in asymptomatic type 2 diabetes.