OBJECTIVE The authors evaluated the use of electron-beam computed tomographic (CT) angiography and three-dimensional (3D) reconstruction for evaluation of coronary artery bypass grafts (CABGs). METHODS Sixty patients (53 men and seven women; mean age, 56 years +/- 8) with 152 CABGs (29 internal mammary artery and 123 saphenous vein grafts) underwent electron-beam CT with 3D reconstruction. The time from bypass surgery to CT scanning was 7 days to 120 months (mean, 17 months +/- 28). Enhanced single-section and flow mode studies were performed in all cases. The results were correlated with CABG operation records, and patency was determined with time-attenuation curves. RESULTS All patients were successfully examined. On the basis of time-attenuation curve criteria, 124 (81.6%) of 152 grafts were patent. The patency rate for the internal mammary artery subgroup was 93% (27 of 29 grafts); for the saphenous vein graft subgroup, 78.9% (97 of 123 grafts). CONCLUSIONS Used in contrast-enhanced, single-section mode and flow studies with time-attenuation curves, electron-beam CT angiography with 3D reconstruction can provide quantitative data for evaluation of CABG patency.