EMATAP, a randomized stratified, placebo-controlled double-blind multicentre trial was performed in Argentina in order to confirm the effect of ticlopidine in the prevention of thrombotic events in patients with intermittent claudication. Twenty-one clinical centres enrolled 615 patients, 304 (88 diabetic and 216 non diabetic) were assigned to the ticlopidine group and 311 (95 diabetic and 216 non diabetic) to the placebo group. Treatments were given for 24 weeks. The baseline characteristics were identical in both groups. The compliance was good and only 34 patients (17 in each group) did not reach the last visit. Their status however was checked and known at that time and according to the protocol, there was no patient lost to follow-up. Twenty-five patients experienced a first event during the follow-up period and the results show a very dramatic reduction of events in the ticlopidine group (5 vs 20), the difference being highly significant (p = 0.002) in intention-to-treat analysis. If we consider the subgrouping of outcome events: sudden deaths, myocardial infarctions and strokes on the one hand, vascular surgery on the other hand, a significant reduction is found in the ticlopidine group. Taking into account the total deaths plus non-fatal events (9 vs 21), the results were also significant (p = 0.027). These above results therefore demonstrate a consistent reduction in all outcome events. As regard side effects there were fewer gastro-intestinal disturbances and skin reactions than seen in North American trials.(ABSTRACT TRUNCATED AT 250 WORDS)