We present two cases of bone marrow necrosis not associated with malignancy, infection or sickle cell disease. The first case, a 28 year old woman with the antiphospholipid syndrome and a factor V Leiden abnormality, suffered an illness characterised by multiple organ thromboses, anemia and refractory thrombocytopenia. She had documented bone marrow necrosis of the posterior iliac spine and numerous hot spots on bone scanning suggestive of widespread marrow necrosis. This patient also suffered hepatic infarcts and a miscarriage and may represent an explanation for the previously described "catastrophic antiphospholipid syndrome". The second patient developed widespread bone pain over a three week period, underwent a cholecystectomy and suffered major post-operative complications including a delayed transfusion reaction and disseminated intravascular coagulation. Pancytopenia developed and bone marrow trephines from numerous foci revealed widespread bone marrow necrosis. The only predisposing factor to account for this presentation was that the patient had been sniffing glue for two months prior to the illness, as the foci of necrosis had healed on repeat marrow examination eight weeks later when the patient had abstained from glue sniffing. This case may represent a reversible, toxic cause of bone marrow necrosis.