Thymoma is an uncommon slowly growing neoplasm. It usually presents with paraneoplastic syndromes including the immunodeficiency syndrome called Good syndrome and hematological disorders. Pure red cell aplasia is a well-recognized complication of thymoma, and aplastic anemia is very rare in association with GS. We report a case of GS in a heavily treated patient with stage IV thymoma associated with a pure red cell aplasia and an amegakaryocytic thrombocytopenia that evolved into an AA and provide an up-to-date review of the relevant literature. This is the first case of the association of GS and AA with the coexistence of a heavily treated stage IV thymoma. The fatal outcome was not related to the progression of the thymoma, but rather to the severe infectious complications. The combination of lymphopenia and hypogammaglobulinemia typical of GS, coupled to the neutropenia, caused by bone marrow failure, was the main predisposing factor for the unfavourable outcome.