BACKGROUND: No information is available on the long-term results of radial artery (RA) grafts used as coronary artery bypass conduits. METHODS AND RESULTS: In this report, we describe the long-term (105+/-9 months) angiographic results of a series of 90 consecutive patients in whom the RA was used as a coronary artery bypass conduit directly anastomosed to the ascending aorta. The long-term patency and perfect patency rates of the RA were 91.6% and 88%, respectively, versus 97.5% and 96.3% for internal thoracic artery grafts. The severity of stenosis of the target vessel clearly influenced long-term RA patency, whereas location of the target vessel and long-term use of calcium channel blockers did not influence angiographic results. Preserved endothelial function and absence of flow-limiting, fibrous, intimal hyperplasia were also documented. CONCLUSIONS: Ten years after surgery, RA grafts have excellent patency and perfect patency rates. Appropriate surgical technique and correct indication are the key factors for long-term RA patency.