Background: Despite its excellent diagnostic role in evaluating coronary artery disease (CAD), there have been few studies on the value of multi-detector computed tomography (MDCT) as a guidance for determining therapeutic strategies in CAD. We aimed to find out the informations that MDCT can provide for predicting revascularization before coronary angiography (CAG). Methods: We studied 1121 major epicardial arteries (���2mm) of 450 patients undergoing elective CAG for suspected CAD after 64-slice MDCT imaging. All arteries were classified into 3 groups according to percent diameter stenosis (%DS) by MDCT (group1,<30%DS; group2,30%-50%DS; group3,���50%DS). Clinical profiles and MDCT characteristics were obtained. Treatments were decided by angiographic and/or intravascular ultrasound and/or fractional flow reserve guidance and categorized into medical treatment and revascularization consisted of percutaneous coronary intervention and/or bypass surgery. Results: By artery-based comparison between MDCT and CAG, sensitivity, specificity, and positive and negative predictive value for the presence of significant CAD���50% DS were 78%, 93%, 73% and 95%, respectively. Arteries for medical treatment were 650(95%), 138(79%) and 96(36%) and revascularized arteries were 35(5%), 37(21%) and 169(64%) in group 1, 2 and 3, respectively. Hypertension, clinical presentation of acute coronary syndrome (ACS), plaque character and %DS were univariate predictors for revascularization in group 2 which means moderately stenosed CAD by MDCT (p=0.047, p<0.001, p=0.012 and p=0.015, respectively). Among these predictors, clinical presentation of ACS [odds ratio(OR)=6.963, 95% confidence interval(CI) 2.577-18.817] and %DS (OR=1.126, 95% CI 1.026-1.236) were independent predictors of revascularization in this group 2. Conclusions: Although 64-slice MDCT has high negative predictive value for diagnosis of significant CAD, one fifth of coronary arteries with moderate, non-significant stenosis by MDCT imaging were treated with revascularization. In clinical application of 64-slice MDCT, we need more careful assessment in the patients with high probability of ACS and with higher %DS even in the moderately stenosed coronary lesions by MDCT.