Previous studies clearly demonstrated the efficacy of antiplatelet drugs for secondary prevention of atherothrombosis in patients with atherosclerotic diseases. However, clinical events still occur in some patients despite receiving conventional antiplatelet therapy. Recently several new drugs have been developed to further improve the efficacy of antiplatelet agents. Prasugrel, ticagrelor and cangrelor are new P2Y₁₂ receptor antagonists that possess better metabolic profiles than clopidogrel, and show more potent and consistent efficacy for the inhibition of platelet aggregation. In patients with acute coronary syndrome (ACS), prasugrel and ticagrelor were superior to clopidogrel in reducing cardiovascular events, although intravenous cangrelor did not show superiority over clopidogrel. The thrombin receptor antagonist SCH-530348 showed a trend to reduce ischemic events without significantly increasing major bleeding in patients with ACS receiving both aspirin and clopidogrel in a phase 2 study. Results of ongoing clinical trials will provide further insight on the clinical benefits of these new antiplatelet drugs for the treatment of atheroembolic diseases.