A 72-year-old woman with refractory anemia had severe bleeding tendency. Since 1994, platelet transfusions (10 units three times per week) were unable to maintaining her platelet count over 10 x 10(3)/ microliter. Her hemoglobin was decreased to 3.9 g/dl as a result of bleeding from early gastric cancer. At one-hour after posttransfusion corrected platelet count increment (1-hour CCI) was slightly low, as 14 x 10(3)/microliter/m2. A 24-hour posttransfusion CCI (24-hour CCI) and the (24-hour CCI)/(1-hour CCI) ratio were markedly low, as 0.5/microliter/m2 and 0.36, respectively. Anti-HLA antibody was not detected. The ineffectiveness of platelet transfusion was suspected to be highly associated with splenomegaly. Her spleen had been gradually increased in size since the first clinical examination. She underwent both subtotal gastrectomy and splenectomy, while receiving 40 units of platelet transfusion. After splenectomy, the 1-hour CCI and the (1-hour CCI)/(24-hour CCI) ratio markedly improved (76 x 10(3)/microliter/m2 and 0.79, respectively). Cutaneous bleeding halted and there have been no further episodes, despite less frequent platelet transfusions. This is the first report in which bleeding tendency and CCI were improved by splenectomy in a case of myelodysplastic syndrome.