Directional atherectomy has proved useful in the treatment of peripheral vascular occlusive disease, and the authors have begun using this modality in the treatment of patients with failing hemodialysis access fistulas. The authors describe their initial experience with 13 patients in whom directional atherectomy was used to treat stenotic hemodialysis fistulas. Directional atherectomy was the sole treatment modality for eight patients. Three patients underwent atherectomy after unsuccessful percutaneous transluminal angioplasty (PTA). In two patients, unsuccessful atherectomy necessitated subsequent PTA. Directional atherectomy was successful in 10 of 13 patients. In seven of these 10 patients who are still alive, the dialysis fistulas remain patent. Directional atherectomy is a safe and useful technique in the percutaneous treatment of hemodialysis fistula stenosis. Early data indicate patency rates that may be higher than those reported with PTA.