A 35-year-old woman was admitted to hospital because of epistaxis, hematomas, and metrorrhagia. Laboratory data indicated severe coagulopathy with prolonged prothrombin time and decreased serum concentrations of vitamin K-dependent clotting factors II, VII, IX, and X. The patient denied taking any oral anticoagulants. She was given transfusions of red blood cells, fresh frozen plasma (1,180 mL) and phytomenadione daily for 6 weeks (total dose 550 mg), which normalized the coagulation factors concentration. After all other possible causes of acquired coagulopathy had been excluded, rodenticide poisoning was suspected on the basis of her epidemiologic history. The patient was a war refugee from Bosnia and Herzegovina. During her absence, the troops of United Nations Protection Force performed rodent extermination in and around her house. History data and therapeutic effects suggested that the coagulopathy had been caused by prolonged exposure to long-acting anticoagulant rodenticide. This could also explain the need for protracted phytomenadione therapy.