PURPOSE: To evaluate the diagnostic accuracy of non-invasive coronary angiography by electron beam tomography(EBT) for the depiction of coronary artery stenosis, as compared with conventional coronary angiography. MATERIALS AND METHODS: In 20 patients with no history of coronary artery disease, EBT (Imatron C-150) study was performed with EKG-gating. Forty images were obtained in each patient from the pulmonary trunk to the cardiac base at 80% R-R interval, and data were reconstructed into a three-dimensional coronary angiography. The interval between conventional coronary arteriograpy and EBT was less than 30 (mean, 9) days. Coronary arteries were divided into seven segments, and stenosis was defined as a narrowing of the luminal diameter of the coronary artery of more than 50 %. The results of EBT and of conventional angiography were compared for diagnostic accuracy. RESULTS: Conventional argiography revealed significant stenosis of the coronary artery in 12 of the 20 patients, while the use of three-dimensional coronary angiography by EBT revealed this in 16. The sensitivity and specificity of EBT were relatively high in the depiction of stenosis in the proximal left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA) and middle LAD, but low sensitivity in the middle LCx and RCA. In the left main coronary artery, sensitivity was 50%. The sensitivity, specificity, accuracy, and positive and negative predictive values for the depiction of coronary artery stenosis with three-dimensional coronary arteriography by EBT were 79%, 95 %, 93 %, 71%, and 97 %, respectively. CONCLUSION: Three-dimensional coronary angiography by EBT is a non-invasive diagnostic modality for the depiction of proximal epicardial coronary artery stenosis and appears to be useful for excluding the probability of ischemic heart disease in a selected patient group.