From February 1988 to September 1992, six patients with Stage III or IV invasive thymoma were enrolled onto our study of multidisciplinary treatment, which included chemotherapy, surgery, and radiotherapy. The chemotherapy consisted of cisplatin (20 mg/m2 continuous 24-hour infusion on days 1 through 4), doxorubicin (40 mg/m2 on day 1), and methylprednisolone (1,000 mg on days 1 through 4 and 500 mg days 5 and 6). Two patients received surgery (incomplete resection) and postoperative chemo/radiotherapy, and four patients received induction chemotherapy followed by surgery and chemo/radiotherapy. All patients with induction chemotherapy showed a partial response and underwent complete (n = 2) or partial (n = 2) resection. Four patients are alive with no evidence of disease for 31 to 55 months after the diagnoses. But two with partial resection after chemotherapy died of recurrent disease. Multidisciplinary treatment including chemotherapy may be a new therapeutic choice in management of advanced invasive thymoma.