Late-onset renal failure occurs in up to 20% of survivors of bone marrow transplantation. Total body irradiation is a major factor in this syndrome, so-called bone marrow transplant nephropathy (BMT NP), which is defined by disproportionate anemia, hypertension, and azotemia. Previous or concurrent chemotherapy may potentiate the effect of radiation on the kidney. Kidney function may decline acutely or more gradually, with eventual long-term stabilization. Patient survival is associated with control of the blood pressure. BMT NP is a recognized complication of bone marrow transplantation, which will require ongoing attention.