A 25-year-old female patient was adimitted due to discomfort in the right chest and left epigastric area. Chest X-ray and chest CT showed a round 4$ imes$4$ imes$4cm sized mass located in the right lower lobe and abutted on the right diaphragm and metastatic lesions in the right lower lobe and right middle lobe. In exploratory thoracotomy, we discovered a mass originating from the right diaphragm which directly invaded the right lower lobe and metastatic subpleural lesions in the right lower lobe and right middle lobe. The mass was diagnosed as sarcoma by frozen section biopsy and we removed the mass by on bloc resection of the right diaphragm and right lower lobe. Metastatic subpleural lesions in the right lower lobe and right middle lobe were removed by wedge resection. The mass was malignant fibrous histiocytoma of the diaphragm in permanent pathologic examination and chemotherapy was done as adjuvant measure. We report one extremely rare case of malignant fibrous histiocytoma of the diaphragm with literature.