Hemostasis is the physiological process that stops bleeding. In the case of a procoagulantly disrupted hemostatic balance, thrombosis occurs. Anticoagulant drugs enable the prevention and treatment of thromboembolic incidents by inhibiting clotting factors. It is important to recognize conditions in which prophylaxis or treatment is necessary. The most important indications for introducing anticoagulant therapy are arterial and venous thromboembolism, heart valve diseases, the presence of artificial valves, atrial fibrillation, myocardial infarction, perioperative and postoperative prophylaxis and prophylaxis in other prothrombogenic diseases and conditions. Depending on o the route of administration, anticoagulants are divided into parenteral and oral. Parenteral anticoagulant drugs include unfractionated heparin, low molecular weight heparin, fondaparinux and argatroban. Oral anticoagulant drugs are categorized into vitamin K antagonists and direct oral anticoagulants (DOACs). The most common representative of vitamin K antagonists is warfarin. Direct oral anticoagulant drugs cause thrombin inhibition (dabigatran) or factor Xa inhibition (rivaroxaban, apixaban, edoxaban). This thesis presents the characteristics of parenteral and oral anticoagulant drugs that are currently available in modern clinical practice, their pharmacodynamics, pharmacokinetics, dosages, clinical indications and contraindications, and side effects.