Reoperations solely for myocardial revascularization were performed in 219 consecutive patients (1967 to 1975). Indications were (1) graft failure, 46 (21 per cent); (2) progressive atherosclerosis, 42 (19 per cent); (3) incomplete revascularization, 39 (18 per cent); and (4) combinations, 92 (42 per cent). Primary operations included bypass grafts in 100 patients; mammary artery implants, 87; and combinations of direct and indirect procedures, 32. Reoperations performed were single bypass, 141 patients; double, 61; and triple or other coronary artery operations, 17. Eight patients died within 30 days of operation (3.7 per cent). Major postoperative complications included hepatitis, 24 (11 per cent); myocardial infarction, 19 (9 per cent); bleeding, 21 (10 per cent); and respiratory insufficiency, 12 (5 per cent). Follow-up for 202 long-term survivors was complete (mean 29 months). In patients who originally underwent direct revascularization, Class I or II (N.Y.H.A.) was attained in 35 of 43 (81 per cent) of those reoperated upon for primary graft failure, in 14 of 15 (93 per cent) of those with progressive atherosclerosis, and in 27 of 33 (82 per cent) of patients with combined indications. Arteriography was performed after the reoperation in 55 patients (mean interval 17 months), and 65 of 77 (84 per cent) grafts were patent. Nineteen of 22 grafts performed for primary graft failure were patent. We have made the following conclusions: (1) Reoperation for direct myocardial revascularization can be accomplished with low mortality rates although morbidity is high; (2) complete relief of symptoms was achieved in 65 per cent of survivors; (3) results in patients reoperated upon for graft failure alone were similar to results in those operated upon for progressive atherosclerosis or combined indications; and (4) high graft patency was found in secondary grafts constructed to arteries involved with primary graft failure.