About 25 to 30% of patients with idiopathic thrombocytopenic purpura (ITP) are resistant to standard treatment with steroids and splenectomy. In these patients with chronic refractory ITP, there is no proven algorithm for standard care. Recently, the chimeric anti-CD20 monoclonal antibody rituximab was considered as an alternative treatment option in this patient group. We present a patient with frequently relapsing ITP after treatment with prednisone, splenectomy and high-dose dexamethasone. Since he experienced increasing side effects due to the steroids, he was treated with rituximab 375 mg/m2, once weekly for four weeks, resulting in a complete long-lasting response (follow-up seven months).