Stem cell transplantation (SCT) nephropathy is 1 cause of chronic kidney disease in patients after allogeneic SCT. It is a thrombotic microangiopathic syndrome characterized by raised creatinine, hypertension, and anemia. The difference with thrombotic thrombocytopenic purpura (TTP)-like syndromes is that it occurs later than 3 months after SCT, has marked renal dysfunction, and occurs in the absence of other complications or nephrotoxic medication. Total-body irradiation (TBI) in combination with previous chemotherapy is most likely the cause. We describe 6 cases of SCT nephropathy that occurred in a cohort of 363 patients who received myeloablative allogeneic SCT. All patients had TBI with shielding of the kidneys. We discuss the course of the syndrome, treatment, and outcome of the patients.