The authors describe the cases of three patients affected by acute myeloid leukemia, in complete remission, who rapidly developed neurologic symptoms leading to death. Neither clinical characteristics, nor radiological or microbiological procedures, allowed an etiological diagnosis of the neurologic syndrome. Post-mortem examination of the brain showed both macroscopic and microscopic findings compatible with acute hemorrhagic leukoencephalitis. The difficulty in distinguishing this entity from other CNS disease-related complications (e.g. leukemia infiltration, drug toxicity, hemorrhages) should not lead to an underestimation of the true incidence of this complication. We believe that with more attention to the possibility of this complication there would probably be both a greater possibility of collecting clinical informations about the real impact of this dramatic disease and a stronger hope of finding the right treatment for it.