Purpose: In patients presenting with suspected or known coronary artery disease (CAD), assessment of prognosis is essential in selecting appropriate patient management. Until now, noninvasive evaluation of symptomatic patients has primarily relied on stress muclear myocardial perfusion imaging and echocardiography. Recently, multidetector computed tomography(MDCT) has been used for risk strarification in patients with known or suspected CAD. The purpose of this study was to determine the association of cardiac events with severity and extent of CAD on MDCT. Methods: We studied 1,814 patients (817 males and 997 females aged 61.7짹12.3 years) with known or suspected CAD undergoing 64-slice MDCT. The patients had no prior history of revascularization. The severity and extent of CAD, plaque of coronary arteries were analyzed. Patients were followed up for the occurrence of: 1) cardiac death, 2) nonfatal myocardial infarction 3) unstable angina requiring hospitalization, and 4) revascularization. Results: The 904 patients (49.8%) had CAD. During mean follow-up 293.26짹192.62 days, 50 patients had experienced cardiac events. Higher event rates were observed in patients with obstructive CAD ( > 50% luminal stenosis) (8.7% vs 2.4% in non-obstructive CAD vs 0.3% in normal ,p=0.000). In univariate analysis, hypertension (odds ratio (OR) 1.974, p=0.019), presence of plaque in proximal LAD (OR 3.596. p=0.001) and proximal RCA (OR 2.126,p=0.011), obstructive CAD (OR 2.325, p=0.000) is significantly associated with cardiac events. In multivariate analysis, significant predictor of cardiac event was obstructive CAD (OR 1.8, p=0.03). Conclusions: In our study, the presence of obstructive CAD was significant predictor of adverse cardiac events. MDCT might predict cardiac events in known or suspected CAD.