SummaryThe role of platelets in arterial thrombosis explains the interest of platelet kinetics.The platelet turnover is increased in evolutive arterial thrombosis, in patients with rheumatic heart disease or with substitute heart valves and in patients with active arterial disease.Correction of the increased platelet turnover is observed after treatment with platelet blocking agents.Patients with high risk of thromboembolism could possibly be recognized by means of platelet kinetics.