A 42-year-old man with chronic myelogenous leukemia underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) from an unrelated donor in January 1998. About 100 days later, he developed skin eruption and a diagnosis of chronic graft-versus-host disease (cGVHD) was made by skin biopsy. The eruption improved with steroid therapy, and the dose of steroid was gradually tapered. On day 151, the patient developed nephrotic syndrome with proteinuria up to 20 g/day. A renal biopsy carried out on day 160 showed minimal change in the glomeruli. The proteinuria disappeared 19 days after the onset of nephrotic syndrome without any additional therapy, and no recurrence was observed upon re-tapering of the steroid. In this case, cGVHD might have been related to development of the nephrotic syndrome. Nephrotic syndrome after allo-HSCT is a rare complication, and only ten cases have been reported. The histological findings were mainly membranous nephropathy, and immunosuppressive therapy was effective. As seen in this case, transient nephrotic syndrome with cGVHD may occur after allo-HSCT, and care is necessary to ensure that treatment of cGVHD is sufficient.