To date, a recognized treatment for refractory membranous nephropathy (MN) has not been established. Recently, several reports have indicated the efficacy of rituximab as a novel treatment option. However, only a few published accounts exist of rituximab therapy for idiopathic MN (IMN) in the Asian population. We present the cases of three IMN patients who were treated with single-dose rituximab after they showed no response to conventional therapies, including corticosteroids, cyclosporine, cyclophosphamide, mizoribine, and mycophenolate mofetil. Although one case showed no response, a complete or incomplete remission was achieved in the other two cases. Rituximab may therefore be a beneficial treatment option for IMN.