Objective To evaluate the outcome of percutaneous intervention for the diseased bypass grafts in patients with previous coronary artery bypass graft surgery (CABG).Methods Sixty-six patients with diseased grafts after CABG underwent percutaneous intervention between July 2003 and July 2004.Angiographic follow up was suggested to all patients and major adverse cardiac events(MACE,including death,acute myocardial infarction and target lesion revascularization)were recorded within 6 months of follow up.Results Sixty-six patients with 74 diseased grafts(83 lesions) underwent percutaneous intervention.The angiographic success rate was 96.97%((64/66)) and the procedural success rate was 95.45%(63/66).No reflow phenomenon occurred in 2 cases,1 case restored TIMI 3 flow after administering verpamil but the other patient failed to restore the blood flow. Distal embolization occurred in 1 case.Abrupt closure in 1 case because of Dtype dissection not treated during the procedure but TIMI 3 flow was obtained after repairment with another stent.No MACE(death,acute myocardial infarction and acute emergency revascularization) occurred during hospitalization and the incidence of MACE was 31.3%(20/64) at 6 months follow up.In-segment restenosis rate was 32.5%(13/40) in 37 patients with angiographic follow-up.Conclusion Percutaneous intervention for diseased bypass grafts is feasible,safe and effective.