Early and late (range 5-73 months, average 2.5 years) postoperative arteriographic studies were performed in 85 patients after saphenous vein aortocoronary bypass surgery. In a prior study (≤ 2 weeks postoperative) of 570 patients with 1197 grafts, arteriography revealed 89.6% early patency of grafts. Late follow-up in 85 patients discharged with all grafts patent revealed 92.2% still patent, an annual mean graft attrition rate (percent of grafts closed/year) of 3.2%/year. This mean graft attrition rate was only slightly affected by regrouping patients according to the interval between the two postoperative studies; however, recurrent angina pectoris was influenced by vein graft attrition. Thus, in 36 patients restudied because of recurrent angina pectoris, the attrition rate was 6.1%/year, compared with 1.1%/year in 49 patients without angina. Progressive coronary artery disease (41% vs 18%), graft closure (22% vs 4%) and incomplete revascularization (39% vs 16%) were significantly more frequent in those with recurrent angina. The frequency of progressive coronary disease was directly related to the duration of follow-up (i.e., the longer the follow-up the higher the frequency of progressive disease). The mean annual rate of progressive coronary disease in arteries not grafted was 11.8%/year. Kinking or graft stenosis was observed in 3.1% of grafts in the early study, while late localized graft narrowing was observed in 8%. At late follow-up, most patent grafts were uniformly narrowed and foreshortened. The mean graft diameter decreased by 17% at late follow-up, and 25% of grafts had at least 25% reduction in mean diameter; however, the mean graft diameter/mean recipient artery diameter ratio exceeded 1.0 in all but one graft. The graft/artery diameter ratio at late follow-up was over 1.5 in 71% of the grafts. The mean graft blood flow determined by cinedensitometric methods revealed a 30% or more reduction in blood flow in 35% of grafts, compared with early postoperative measurements.