Solitary fibrous tumors of the pleura are neoplasms of the mesenchymal tissue of the pleural mesothelium. The most frequent symptoms are dyspnea, coughing and chest pain. A 45-year-old female patient presented after a thoracic contusion. A radio-opaque image was evidenced on chest X-ray. At the initial hospital, a hemorrhagic fluid was aspirated at thoracocentesis and the patient was transferred to our hospital with diagnosis of traumatic hemothorax. A thoracic CT showed a tumoral formation filling two-thirds of the left hemithorax. The transthoracic biopsy finding wits compatible with a fibrous tumor. The patient was taken for surgery and the large pleural tumor was excised. In conclusion. a large pleural fibrous tumor was initially mistaken for hemothorax. A CT-scan revealed the tumoral nature of the thoracic opacity.