In a retrospective study the indications and the long-term results of percutaneous atherectomy of a nonselected group of patients were analysed. From March 1988 to November 1989, 94 patients suffering from peripheral vascular disease were treated using Simpson's atherectomy technique. There were 132 lesions, 101 stenoses and 31 occlusions in a total of 94 patients. The primary success rate was 95%. After 12 months of follow-up the cumulative patency rate was 69% and after 24 months, 42%. After a follow-up period of 15 months patent arteries and recurrences were recorded and the results used to analyse the factors that influence patency after Simpson atherectomy. The patency rate is 71% in diabetics and 62% in non-diabetics. It is 51% in occlusions and 73% in stenoses. The patency rate in patients with fair runoff is 69%, in patients with poor runoff 60%. Comparing these results with historical studies concerning balloon dilation the results are poor. Residual stenoses after balloon dilation seem to be the optimal indication for percutaneous atherectomy.