Percutaneous atherectomy was performed using the Simpson Atherocath on 131 patients (87 male, 66%) with a mean age of 65 years. Clinical characteristics included evidence of significant coronary disease in 50%, hypertension in 46%, diabetes in 41%, and prior neurologic deficit in 32% of patients. The indication for atherectomy was claudication in 114 (87%) and rest pain, gangrene, or ulcer in 17 patients (13%). Atherectomy was successfully performed in 136/139 stenoses (98%) and in 56/56 occluded vessels with or without prior balloon angioplasty. No serious complications resulting in limb loss or emergency vascular surgery were encountered. Histopathology of retrieved specimens showed that 66% had atheromatous plaque, 45% had tunica media, and 30% had a form of thrombus. Material obtained from an occluded vessel was more likely to have thrombus and tunica media present than that from a stenosis (P less than 0.02 and P less than 0.05, respectively). Early angiographic follow-up (mean time, 17 weeks) showed a relatively low (17%) lesion recurrence rate. Percutaneous atherectomy can be successfully utilized in stenotic and occluded peripheral arteries with good success and no serious complications; stenoses appear to have a low recurrence rate.