A 68-year-old man was noted to have an abnormal shadow on chest X-ray. Chest computed tomography (CT) showed a 100 mm mass in the lower right thoracic cavity. The mass was lobulated and compressed the surrounding lung tissue and diaphragm. Contrast-enhanced CT showed that the mass was heterogeneously enhanced and contained expanded blood vessels within it. The expanded vessels communicated with the pulmonary artery and vein via the diaphragmatic surface of the right lung. The mass was diagnosed as a solitary fibrous tumor of the pleura (SFTP) by CT-guided lung biopsy. We performed partial resection of the lung including the tumor via right eighth intercostal lateral thoracotomy. Intraoperative examination showed that the tumor was pediculated from the diaphragmatic surface of the right lung. The stem was about 3 cm long and easily cut with a stapler. The tumor was definitively diagnosed as a malignant SFTP. No recurrence was found for 12 months postoperatively.