Thrombosis of arteriovenous fistulas is usually superimposed on underlying stenosis in the arterial anastomosis, draining vein, or central vein. Restoring the patency of thrombosed fistulas requires mechanical thrombectomy, in conjunction with angioplasty of the underlying lesion. We evaluated the success rate of percutaneous thrombectomy of fistulas at our medical center. We retrospectively queried a prospective, computerized vascular access database to identify 41 patients with thrombosed fistulas treated percutaneously. Technical success was defined as the ability to use the fistula for at least one dialysis session. Primary patency was defined as time to the next intervention, and secondary failure as the time to permanent fistula failure. Of the 41 thrombosed fistulas, 21 were in the forearm and 20 in the upper arm. Percutaneous thrombectomy was technically successful in 31 of 41 patients (76%). The technical success rate was similar for upper arm and forearm fistulas (85% vs. 66%, p = 0.43). An underlying stenotic lesion was present at the arterial anastomosis in 13 patients (31%), in the draining vein in 37 (90%), and in the central vein in 3 patients (7%). Twelve patients (29%) had concurrent stenoses at two locations. At 6 months, the primary patency was 20%, and the secondary patency was 54%. In conclusion, percutaneous treatment of thrombosed fistulas can restore fistula patency about three-fourths of patients. However, the primary fistula patency is fairly short-lived, and the fistulas require repeated interventions to achieve long-term survival. © 2008 Wiley Periodicals, Inc.