To evaluate the value of angiographic factors in predicting failure of both venous and arterial coronary artery bypass graft. We retrieved from our angiographic database 148 patients who underwent venous and/or arterial CABG and for whom a control coronary angiography at more than 1 month after surgery was available. Pre-CABG and follow-up angiographies were analyzed in order to evaluate diameter stenosis (DS,%), stenosis length (mm), Bogaty score (extent index), Sullivan score, and Gensini score for the extent of coronary artery disease, and Jeopardy Duke score for the extent of myocardial area supplied by an artery. Thirty-nine patients (26%) experienced graft failure at follow-up (mean follow-up 11.3 ± 4.6 months). Patients with venous graft failure [26 (20%)] had significantly smaller DS (P = 0.013), shorter stenosis length (P = 0.01), and lower extent index (P = 0.015), Sullivan score (P = 0.013), Gensini score (P = 0.04) as compared with those without venous graft failure. Patients with arterial graft failure [13 (11%)] had significantly lower DS (P = 0.008), shorter stenosis length (P = 0.001), and lower extent index (P = 0.03) and Sullivan score (P = 0.023) as compared with those without arterial graft failure. Venous and arterial graft failure are associated with less severe stenosis and less extensive atherosclerosis of the grafted vessel.