We herein reported a 75-year-old man who presented to our hospital with hypoglycemia. Blood tests revealed that insulin secretion was suppressed, and serum concentrations of insulin-like growth factor (IGF) -1 and IGF-II did not increase. However, Western blot analysis suggested the presence of big IGF-II in his serum. Chest computed tomography showed a well-demarcated solid mass, 20 cm in the longest diameter, containing heterogenous components in the left thoracic cavity. Fine needle biopsy suggested a solitary fibrous tumor. Operative findings showed a solid tumor attached by a pedicle to the diaphragmatic portion of the left visceral pleura after left thoracotomy. Tumor resection and concomitant partial pulmonary resection of the left lower lobe was successful. Operation time was 209 min and blood loss was 220 ml. Diagnosis of a malignant solitary fibrous tumor arising from the visceral pleura producing big IGF-II was made by immunohistochemical staining. Hypoglycemia had not been documented just after surgery. No tumor recurrence is found 3.5 years after surgery.