Poor long-term patency of saphenous vein grafts limits the long-term success of the coronary artery bypass operation. If this is to be improved, either measures that increase the patency of saphenous vein grafts or alternative conduits are required. The benefits of using the left internal mammary artery as a pedicled graft to the left anterior descending coronary artery have prompted increasing use of arterial grafts to further improve outcome. Concurrently advances in the understanding of the pathological processes underlying saphenous vein graft occlusion raise the possibility of improving vein graft patency. In this paper we review the problem of vein graft occlusion and possible solutions, the theoretical benefits of arterial grafts and the clinical results associated with their use.