Thoracoscopic surgery for empyema thoracis treatment is still uncommon in Japan. We report a case of chronic empyema thoracis which was successfully treated with decortication through thoracoscopy. A 63-year-old man presented with respiratory distress, appetite loss and hoarseness. He had been suffering from diabetes mellitus for 13 months. His chest X-ray film revealed that he had suffered from the left chronic empyema. As the decortication procedure was feasible at the preliminary exploration, it was then performed through the thoracoscopy. The lung re-expanded well after the pleural peel was removed. His chest drainage tube was drawn out on 19th postoperative day.