Legionnaires' disease in a 37-year-old male who had had silicosis was reported. He was admitted because of dyspnea. The chest X-ray film and CT scan showed infiltrative shadow and swelling of mediastinal lymph nodes. Open lung biopsy was done and Legionella pneumohila was detected. REP and EM were started and infiltrative shadow of X-ray was disappeared. Pleuro-pneumonectomy and thoracoplasty were performed because of hemoptysis and postoperative empyema. The patient is now well.