The major complications of myelodysplastic syndromes are related to cytopenia and evolution to acute myeloid leukemia. Bleeding episodes in MDS, although relatively uncommon, are often related to thrombocytopenia. Bleeding may be exacerbated by platelet dysfunction, which is also found frequently. Furthermore, the major hemostatic problem underlying hyperleukocytosis, as evident in patients with MDS on blast crisis, appears to be hemorrhage rather than thrombosis. Acute thromboembolism, which causes occlusion of blood supply and organ infarction, has rarely been observed in patients with MDS. Recently, we encountered an elderly female patient, who had chronic myelomonocytic leukemia with marked myelodysplasia, terminating in blast crisis and bilateral renal infarction. This complication rapidly led to oliguric acute renal failure and mortality.