A 67 year old man presented with non-invasive thymoma, associated aplastic anemia and important hypogammaglobulinemia; the postoperative course has been characterized, three months later, by thrombocytopenia (kept under control with steroid therapy) and, two years later, by squamous lung cancer, not susceptible of surgical treatment. The patient died five years after operation because of progression of the lung cancer. Anemia improved only partially after operation; there where no effects on hypogammaglobulinemia. Thymoma has been reported in literature in 50% of patients with aplastic anemia, 7-13% of adult patients with hypogammaglobulinemia is affected by thymoma, in 21% of patients that presented with thymoma other tumors have been discovered through clinical history.