Indobufen--an inhibitor of platelets aggregation--has been used in 306 patients with intermittent claudication due to peripheral vascular disease. Patients were treated and followed up for one year. One patient of every 3 treated with indobufen was treated with ASA, and a control group of patients receiving no treatment was also followed up. The authors studied by means of a treadmill exercise test the pain-free walking distance (PFWD), the global walking distance (GWD), and the recovery time after exercise. The treatment period was completed by 290 patients: 204 claudicants, 51 claudicants with diabetes, and 35 with a short PFWD and GWD (greater than 150 m). Indobufen was more effective than ASA in improving the PFWD and GWD in all groups. There were also fewer side effects with indobufen, and cardiac morbidity and mortality was also reduced. In conclusion indobufen showed its activity and safety in chronic treatment of patients with peripheral disease, and we suggest that it may be used for long periods without side effects.