Improving survival rates after pediatric bone marrow transplantation will likely result in greater numbers of early and late renal complications. We designed a retrospective study to evaluate the incidence of renal involvement on 120 bone marrow recipients referred to the pediatric nephrology outpatient clinic between 2003 and 2005. These complications were found in 4 cases (3 female and 1 male) including membranous nephropathy (n=2), hemolytic uremic syndrome (n=1) and cyclosporine nephrotoxicity (n=1). The underlying diseases were major thalassemia, aplastic anemia, and leukemia and leukocyte adhesion deficiency (LAD) syndrome. Mean age was 7.3 year. Hemolytic uremic syndrome was occurred in early period (2 months) following transplantation, the rest were seen between 3-12 months. Fortunately, our patient with hemolytic uremic syndrome completely responded to plasmapheresis. Heavy proteinuria in membranous nephropathy cases was significantly reduced by ACE inhibitors. Renal impairment in last case was improved by reducing the dose of cyclosporine. Early diagnosis and prompt management of renal involvement are essential for graft salvage and may greatly improve prognosis.