Bleeding is probably the major complication of anticoagulant treatment with vitamin K antagonists represented nowadays mostly by warfarin in the Czech Republic. The main risk factors in hemorrhagic complications of warfarinisation are the intensity and instability of the anticoagulant treatment, individual patient characteristics, warfarin interactions with other drugs and the length of the anticoagulant therapy. Severe bleeding in warfarin patients is most effectively brought about by a fast and complete undoing of the anticoagulation effect of the drug employing the prothrombin complex concentrate and slow i.v. vitamin K1 infusion regardless of the reason for the anticoagulation. This approach can secure the minimalisation of the bleeding's negative consequences. A less severe bleeding or asymptomatic increase in the international normalized ratio can be treated effectively by skipping or decreasing of the warfarin dosage and/or oral administration of vitamin K1 (i.v. administration only in selected higher risk cases) that does result only in a partial consolidation of coagulopathy but of such type that the risk of thrombotic event requires. The article's goal is to contribute to the treatment standardization in patients with warfarin overdose and/or with hemorrhagic complications due to warfarin treatment and it is available at www.thrombosis.cz. The guidelines include a ready-reference chart whose objective is immediate and quick crash course in the clinical practice.