The Swedish Ticlopidine Multicentre Study (STIMS) was a double-blind placebo-controlled trial designed to determine whether ticlopidine, a platelet antiaggregatory agent, reduces the incidence of myocardial infarction, stroke and transitory ischaemic attacks in patients with intermittent claudication. A total of 687 patients was monitored for a minimum of 5 years or until an end-point was reached. The number of end points (99 vs. 89), analysed according to the intention-to-treat principle, was 11.4% lower in the ticlopidine group (P = 0.24). The mortality rate was 29.1% lower in the ticlopidine group (64 vs. 89, P = 0.015); this observation could be accounted for by a reduced mortality from ischaemic heart disease. On-treatment analysis showed there to be significantly fewer end points in the ticlopidine group (47 vs. 76, P = 0.017). Diarrhoea was the most common side-effect. Reversible leucopenia or thrombocytopenia was reported in seven patients on ticlopidine. It is concluded that the high morbidity and mortality from cardio- and cerebrovascular disease in patients with intermittent claudication can be reduced by long-term treatment with ticlopidine.