Acute erythroleukemia is a rare subtype of acute myeloid leukemia that has undergone several changes in classification over the past 30 years. There are two subtypes of acute erythroleukemia: the more common erythroid/myeloid subtype, defined by the presence of increased erythroid cells and myeloid blasts; and the rarer, pure erythroid subtype, characterized by expansion of immature erythroid cells only. The erythroid/myeloid subtype of acute erythroleukemia is closely related to acute myeloid leukemia with myelodysplasia-related changes, and is frequently characterized by morphological dysplasia and complex karyotype. Pure erythroleukemia is a very uncommon subtype of leukemia associated with a very poor response and survival to current available therapeutic agents. Treatment results for this disease are suboptimal and new drugs are needed. This article summarizes current knowledge in the field of acute erythroleukemia.