A 68-year-old man with recurrent bilateral severe pneumonia and invasive thymic carcinoma was admitted to our hospital. An extended thymo-thymectomy with lymph nodes dissection was performed for an irregular shaped anterior mediastinum mass. The tumor was mainly composed of type C, adenosquamous carcinoma, and found to have a small area of types B2 and B3 thymoma. History and laboratory findings were compatible with the diagnosis of Good syndrome. Although there are some reports of thymic carcinoma arising from thymoma, this is the first report of co-existence of adenosquamous carcinomas and thymoma with Good syndrome as far as reviewed articles. Thymic carcinoma with severe infection should be examined carefully for co-existence of thymoma, and co-existence of thymoma and thymic carcinoma suggests a close histogenetic relationship between the 2 tumors.