We report a 67-year-old man who developed pure red cell aplasia (PRCA) during therapy for epilepsy with sodium valproate since April 2004. He was admitted to our hospital because of severe anemia (Hb 5.0g/dl, reticulocyte 0.1%) in August 2004. A bone marrow examination showed marked erythroid hypoplasia and a diagnosis of drug-induced PRCA was made. Because the discontinuation of valproate for one month failed to increase the number of reticulocytes and frequent blood transfusions were necessary, cyclosporine therapy was initiated. Within a week, substantial recovery of the numbers of reticulocytes was obtained, the cyclosporine had, however, to be changed to prednisolone due to the refusal of the patient to continue with it, resulting in the exacerbation of his anemia. After three weeks, cyclosporine therapy was resumed, which achieved rapid and remarkable recovery of red blood cells (Hb 8.9g/dl, reticulocyte 4.9%) within one month. Sixteen cases of valproate-induced PRCA have been reported in the literature and all cases except one recovered only by discontinuing or reducing the administration of valproate. However, our case required cyclosporine therapy in addition to the discontinuation of valproate. These results suggest that not only the direct toxic effect on erythropoiesis but also T lymphocyte-mediated immunological mechanism was involved in the pathogenesis of valproate-induced PRCA.