Bone marrow transplantation (BMT) is an effective therapeutic strategy for leukaemic malignancies and depressed bone marrow following cancer. However, its side effects on kidneys have been reported. Some drugs and irradiation are also suggested to be nephrotoxic. It is well known that haemolytic uraemic syndrome (HUS) after BMT develops as late-onset BMT nephropathy. Cyclosporine A (CsA) is a possible cause. Radiation nephropathy shows changes that are similar to the histology of HUS. These findings suggest that endothelial damage is closely associated with the pathogenesis of post-BMT nephropathy. Recently, some patients have developed glomerulonephritis accompanied by graft-versus-host disease (GVHD) after BMT. In these patients immune deposits are found mainly in subepithelium and mesangium equal to those of secondary membranous glomerulonephritis. A murine experimental model of GVHD manifests similar symptoms and histological changes to those of actual patients and may suggest the pathogenesis of glomerulonephritis.