Bone marrow transplant (BMT) is increasingly being offered as therapy for certain hematologic and other advanced malignancies. We present one representative patient in detail and summarize data from a series of 10 patients who received a BMT and, as a late complication, developed a hemolytic uremic syndrome (HUS). All patients presented with the triad of microangiopathic hemolytic anemia, renal insufficiency and thrombocytopenia from 30 to 875 days after BMT, and despite aggressive supportive management, plasma exchange, IgG administration and/or ex vivo staphylococcal protein A column plasma treatment, eight of 10 patients died from complications related to HUS between 11 to 139 days after diagnosis. In contrast to other reports of HUS after BMT, the present series of patients is heterogeneous with respect to underlying diagnosis, type of BMT (allogeneic or autologous), pretransplant conditioning regimen, presence of graft-versus-host disease, and use of cyclosporin. Additionally, nine of 10 patients were in clinical remission at the time of diagnosis of HUS, and six of 10 patients had achieved a complete recovery following BMT. The cause of HUS in this series of patients is probably multifactorial and related to the intensive pretransplant conditioning regimen.