Abstract: We determined the level of serum acidic isoferritin(AIF) in patients with acuteor chronic leukemia and benign hematologic diseases.This study showed the level ofserum AIF was remarkably increased compared with control.In comparison, therewas no significant difference in the serum level of AIF in both benign hematologicdiseases and normal control.These results suggest that AIF may be a useful markerfor leukemia.