Antithrombotic agents, which are widely used for the prevention and treatment of arterial and venous thrombosis, include antiplatelet drugs and anticoagulants. The antiplatelet agents include oral drugs such as thienopyridines (clopidogrel and prasugrel), ticagrelor, vorapaxar and aspirin, as well as parenteral agents such as cangrelor and glycoprotein IIb/IIIa antagonists. The anticoagulants include parenteral drugs such as heparin, low‐molecular‐weight heparin and fondaparinux and oral drugs such as warfarin and direct oral anticoagulants. This chapter reviews the mechanisms of action, indications, dosing and side effects of these antithrombotic agents.