To evaluate the efficacy, safety, and long-term results of atherectomy using the Transluminal Extraction catheter (TEC), patients with diseased saphenous vein grafts were enrolled in a prospective nonrandomized trial. Patients were followed to hospital discharge for acute complications and underwent routine 6-mo reevaluation with repeat cardiac catheterization to assess restenosis. Atherectomy was performed on 650 graft lesions in 538 consecutive patients (male 81%; mean age 66 yr; range 37-81). Mean graft age was 8.3 yr; (range 0.3-20) with 85% of grafts > 3 yr of age. Complex lesion morphology included thrombus (28%), ulceration (13%), and eccentricity (50%). Lesion success was achieved in 606 lesions (93%) with clinical success in 479 patients (89%). Lesion success was achieved in 90% of thrombus containing lesions, 97% of ulcerated lesions, and 97% of grafts > 3 yr. Complications included nonfatal myocardial infarction in 4 (0.7%) of patients, emergency bypass surgery in 2 (0.41%), and in-hospital death in 17 patients (3.2%). Angiographic follow-up at 6 mo was obtained from 268 lesions in 227 patients. The overall lesion angiographic restenosis rate was 60%. TEC atherectomy can be performed in patients with diseased saphenous vein grafts with high primary success and low complication rates. It is suitable for use in aged grafts, particularly in the presence of thrombus and ulcerations, and may be superior to balloon angioplasty alone in this group of patients.