The state of preservation of 48 coronary saphenous vein grafts was investigated by angiography in 27 patients from 60 to 79 months, average 64.6 months, after their insertion. Thirty-nine of the grafts (81.2 per cent) were patent; of these, 24 (50 per cent) were in excellent, six (12.5 per cent) in good, six (12.5 per cent) in fair and three (6.2 per cent) in poor condition. Nine grafts (18.8 per cent) were occluded. The rate of graft patency in this series compares favorably with that in shorter follow-ups and presages their further prolonged viability. Atherosclerotic obstructive graft disease may emerge as an important cause of late graft deterioration in an occasional patient.