A 64-yr-old patient with myelodysplastic syndrome (MDS), with refractory cytopenia with multilineage dysplasia subtype following chloramphenicol exposure received immunosuppressive treatment with antithymocyte globulin and cyclosporine (CsA). Complete remission was achieved and CsA was tapered after 2.5 yr. Shortly after CsA withdrawal, the patient relapsed with thrombocytopenia but responded to restoration of CsA. This case illustrates that immune-mediated mechanisms of cytopenia in MDS may be dependent on continued immunosuppressive treatment similar to aplastic anemia.