A case of invasive thymoma with pleural disseminations, treated with pleuropneumonectomy and thymectomy , is presented. A 30-year-old woman was admitted with abnormal shadows in left lung field and mediastinum. On chest CT examination, the tumor shadows were located anterior mediastinum and left chest wall. Thymoma with pleural disseminations was the most likely consideration by the needle biopsy specimen of the tumor under left chest wall. Preoperative radiotherapy for anterior mediastinum mass was effective. Pleuropneumonectomy and thymectomy combined with partial resections of intercostal muscles and diaphragm were performed. Histologically, the tumor was arranged in lobular structure, composed of epithelial cells, with poorly infiltration of lymphocytes, and invaded into intercostal muscles or lung. Postoperative radiotherapy for mediastinum and left chest wall was added. Tumors may be removed completely by pan-pleuropneumonectomy and thymectomy for invasive thymoma with pleural disseminations.