A 47-year-old man was diagnosed with non-Hodgkin's lymphoma (NHL) follicular B-cell type (stage IVB). Although partial remission was observed after the administration of several combination chemotherapeutic agents, no more improvement was observed. After we finished the FND (fludarabine, mitoxantrone, dexamethasone) regimen, the patient's status improved. After the administration of the FND regimen, thrombocytopenia developed, and the platelet count did not recover to previous levels. After rituximab was administered for the treatment of thrombocytopenia, the platelet count recovered. Then we combined fludarabine and rituximab for the treatment of NHL. Although fludarabine was administered, the platelet count did not decrease when combined with rituximab. In the discussion, we analyze the characteristics and the treatment outcome of the thrombocytopenia induced by fludarabine reviewed in the literature.