Background In preoperative risk assessment, value of cardiac computed tomography (CT) is still uncertain. We tried to evaluate whether coronary artery calcium score (CACS) and degree of stenosis measured using cardiac CT predict postoperative cardiovascular events in patients undergoing intermediate risk non-cardiac surgery. Methods Between 2007 and 2009, a total of 239 patients were enrolled in the study and underwent cardiac CT before non-cardiac surgeries. We measured CACS and degree of stenosis in cardiac CT and assessed clinical risk factors according to revised cardiac risk score (RCRI: ischemic heart disease, congestive heart failure, cerebrovascular disease, treatment with insulin, and creatinine > 2.0 mg/dL). Postoperative cardiovascular events were defined as acute coronary syndrome, pulmonary edema, ventricular fibrillation, ventricular tachycardia with hemodynamic compromise and complete heart block. In this study, only intermediate risk elective non-cardiac surgeries were included. We excluded patients who were undertaken high or low risk operation and had severe valvular disease, acute coronary syndrome and acute heart failure. Patients with immeasurable CACS were also excluded. Results Nineteen patients (8%, 11 men; 70짹10 years) had experienced postoperative cardiovascular event and 220 patients (114 men; 67짹10 years) had not experienced. Postoperative cardiovascular events were significantly related with history of hypertension, chronic kidney disease, angina and heart failure but not associated with diabetes, smoking and current medication. RCRI (p < 0.001), CACS (p < 0.001), presence of significant coronary artery stenosis (diameter stenosis ��� 50%) (p = 0.01) and multivessel coronary artery disease (p < 0.001) were significantly associated with postoperative cardiovascular events. In receiver operating characteristic (ROC) curve analysis of CACS for predication of postoperative cardiac events, the optimal cut-off value was 110 (sensitivity 79%, specificity 61%, PPV 15%, NPV 97%, AUC 0.762). For the additive value of CACS to clinical risk factors, comparison of ROC curves of five independent predictors of RCRI and RCRI plus CACS (��� 110) was performed. The result suggested that RCRI plus CACS was significantly more predictable than alone of RCRI to postoperative cardiovascular events (AUC of RCRI, 0.675 vs. AUC of RCRI plus CACS, 0.751, p = 0.025). Conclusion In patient undergoing intermediate risk no-cardiac surgery, CACS and coronary artery stenosis of cardiac CT was helpful in postoperative cardiovascular risk stratification. Moreover, CACS showed additive predictive value to RCRI in these patients.