Thrombotic complications constitute a significant problem connected with maintaining arteriovenous fistulas (A-V) for a long time. It has been established that platelets play an important role in the development of thrombosis in high flow systems. Aspirin and dipyridamole do not decrease the frequency of shunt thrombosis. Some of the more recently synthetised antiplatelet drugs (i.e. indobufen, 2-p-oxo-isoindolinyl-phenyl-butyric acid) could be promising in the prevention of such complications. The study group consisted of 40 patients in the terminal stage of renal failure treated with intermittent peritoneal dialysis (IPD). The A-V fistulas were formed by the same surgeon anesthetist team and this allowed for the elimination of technical errors. All patients were divided into two groups. Group I received indobufen at the dose of 2 x 100 mg/24 h orally. Group II received no antiplatelet treatment. The therapy started 24 h before A-V formation. The treatment was continued for 3 weeks. The following tests of platelet function were performed before indobufen therapy, after 9 h and 3 weeks of treatment: ADP and adrenaline induced platelet aggregation, platelet circulating aggregates, MDA level, platelet factor 3 and 4 and bleeding time. During indobufen treatment only a significant decrease in ADP induced aggregation was observed. No prolongation of the bleeding time was noted. No case of fistula thrombosis in indobufen group was observed. This complication, however, appeared in 3 patients (15%) of the control group (without antiplatelet therapy).