A 64-year-old man with treatment-related myelodysplastic syndrome (MDS) underwent non-myeloablative allogeneic peripheral blood stem cell transplantation from a fully HLA-matched sibling. Seven months after transplantation, he suffered from nephrotic syndrome (proteinuria 16.67 g/day) around two weeks atter tapering tacrolimus (TAC) for the prophylaxis of graft-versus-host disease(GVHD). A renal biopsy revealed membranous nephropathy (Stage I ). Treatment with prednisolone (PSL), starting with 50 mg daily, resulted in incomplete remission type I. Although remission was maintained for 7 months, nephrotic syndrome recurred (proteinuria 7.81 g/day)after tapering PSL(5 mg/day) (18 months after transplantation). His PSL dose was increased again to 50 mg daily, and proteinuria improved again. Two weeks after discontinuation of TAC as it was suspected of worsening his renal function, proteinuria increased again to 6.37 g/day (21.5 months after transplantation). After administration of cyclosporin A (CsA) (30 mg/day) instead of TAC, proteinuria re-improved and complete remission of nephrotic syndrome was achieved. In this case, nephrotic syndrome worsened twice just after tapering or discontinuing immunosuppressive medication, and reinforcement of immunosuppression was effective in improving proteinuria. As hematopoietic cell transplantation (HCT) is an increasingly common treatment worldwide, the opportunities to see patients with nephrotic syndrome after HCT are also increasing. Our case serves as a reference to manage the recurrence of nephrotic syndrome after HCT.