The inhibition of platelet function has proved its effectiveness in the reduction of vascular events in many large trials for many different compounds such as ASA, ticlopinin, dipyridamole or clopidogrel. In this overview, the authors analyse the results of recent trials and present ongoing or future trials with clopidogrel. Clopidogrel has proved its superiority in prevention of vascular events as compared to ASA, being even higher in high-risk groups such as diabetic patients. For the post-interventional treatment of patients undergoing stent-protected dilatation of coronary arteries, the combination of ASA and clopidogrel has become a standard procedure. There is also evidence that the combination of ASA and Clopidogrel is better than ASA alone in long-term treatment up to at least 9 months. The long-term combination therapy seems to be very promising and is currently analysed in three large trials in over 30,000 patients with a large number of stroke patients. These trials will also answer the question, whether the combination therapy is safe in long-term secondary stroke prevention. However, there is still a widespread reluctance in doctors to prescribe Clopidogrel for its costs. Cost-effectiveness studies predict up to tenfold higher cost in the prevention of vascular events when compared to ASA, in times of shrinking health budgets a topic of interest.