In a double-blind study, 296 patients with intermittent claudication (Fontaine stage II) were treated with 250 mg ticlopidine twice daily, 500 mg aspirin every third day plus 75 mg dipyridamole three times daily, or 300 mg xanthinol nicotinate three times daily for 6 months. Ticlopidine and aspirin/dipyridamole, but not xanthinol nicotinate, improved platelet aggregation, reduced beta-thromboglobulin, platelet factor IV and fibrinopeptide A concentrations, and increased antithrombin III concentrations and red blood cell filterability. No changes in lipid profiles, platelet count or fibrinogen were recorded following any treatment. The doppler systolic blood pressure ratio was improved in patients treated with ticlopidine or aspirin/dipyridamole, but not with xanthinol nicotinate. It is concluded that antiplatelet treatment is useful for the treatment of limb arteriopathy.