Platelets play an important role in atherothrombotic disease. The currently available antiplatelet drugs target key steps of platelet activation including thromboxane A(2) synthesis, ADP-mediated signaling, and glycoprotein IIb/IIIa-mediated platelet aggregation. The improvement of our understanding on the pharmacokinetic and pharmacodynamic characteristics of these drugs enables the tailoring of the most appropriate anti-thrombotic therapy to the individual patient and risk situation in the daily clinical practice. However, current antiplatelet therapies are associated with increased bleeding risk. Thus, further research on platelet functions may give rise to numerous new antiplatelet agents with high anti-thrombotic efficiency and low adverse hemorrhagic side effects.