From 1977 to 1990, 37 patients with Stage III or IV invasive thymoma (20 men and 17 women; median age, 40 years of age) were referred for chemotherapy to the Padova Medical Oncology Department. All patients initially received the same regimen (50 mg/m2 of cisplatin and 40 mg/m2 of doxorubicin intravenously (IV) on day 1, 0.6 mg/m2 of vincristine IV on day 3, and 700 mg/m2 of cyclophosphamide IV on day 4 [ADOC]), recycling at monthly intervals. No life-threatening side effects were noted. The overall clinical response rate (complete response plus partial response) was 91.8%, with 43% complete remissions. Median duration of response and survival were 12 months (range, 2 to 96+ months) and 15 months (range, 5 to 96+ months), respectively. Seven of the 16 complete remissions were pathologically confirmed at subsequent thoracotomy. Other chemotherapy combinations and radiation therapy have been applied as second-line treatment, achieving only minimal responses. In the opinion of the authors, such chemotherapy deserves evaluation for adjuvant and neo-adjuvant treatment of invasive (and/or inoperable) thymoma due to the high complete response rate and overall response rate.