[A rare complication of oral anticoagulant treatment: hemothorax].

Although bleeding is the most serious complication of oral anticoagulant treatment, hemothorax is extremely rare. Herein, a case with localized pleural plaques and spontaneous hemothorax due to warfarin treatment which was improved with medical treatment is presented because of its rarity. The patients recieving oral anticoagulant treatment should be monitorized for effective anticoagulation and adverse effects, if pleural effusion occurs, hemothorax should be kept in mind in the differential diagnosis. Pleural pathologies such as pleural plaques or thickening may be risk factors for hemothorax.