The 55 years old male patient, undergoing maintenance hemodialysis, was admitted on our department because of painful swelling on left knee joint. At 19th hospital day, he complained of severe dyspnea. He had a large amount of pleural effusion of the left chest that was shown to be hemothorax by thoracentesis. After closed thoracostomy, about amount of 3,000 mL of blood was drained and bleeding was sustained from pleural cavity, and then emergency thoracotomy was done. We cannot find any bleeding focus in thoracic cavity, but oozing blood was seen on entire inner thoracic cavity. He had no previous invasive procedure or history of trauma before 6 months. We think that hemothorax may be developed because of defected coagulopathy and increased bleeding tendency due to platelet dysfunction in renal failure patient. Immediately thoracotomy and cryoprecipitate were helpful for this patient. We report a rare case of spontaneous hemothorax in a maintenance hemodialysis patient with literature review.