Early saphenous vein coronary bypass graft patency has been found to range from 82% to 94%. Recent advances in computed tomography have led to the development of a safe, effective, and "relatively noninvasive" means of assessing early graft patency. We designed a prospective study using contrast-enhanced computed tomography (CECT), postulating that selected grafts might be redone prior to the development of pericardial adhesions if early closure was demonstrated. Forty-three random patients undergoing elective coronary artery bypass comprise the study group. All patients underwent CECT study of graft patency an average of 6 days postoperatively (range 1 to 17 days). Ninety of 96 grafts were open, for an early patency rate of 94%. Three of the grafts were closed because of poor run-off or extensive distal coronary atherosclerosis. Two additional grafts were closed, one in a patient with severe atherosclerosis of the ascending aorta and one in a patient having triple vessel bypass using cephalic vein because of limited conduit material. Only one graft was closed without apparent cause and judged potentially suitable for reoperation. CECT was found to be a safe and potentially useful means of assessing early graft patency, particularly in patients sustaining untoward clinical events.