We describe a case of acute myeloid leukemia (AML) with t(8;21) in which complete remission (CR) was obtained with G-CSF given at 10 microg/kg in the absence of concomitant cytotoxic chemotherapy. CR was achieved following 2 weeks of therapy and confirmed by investigating minimal residual disease by four-color flow cytometry analysis. During treatment with G-CSF, maturing cells with cytoplasmic Auer Rods were observed in the peripheral blood, suggesting a differentiation effect. This case adds further evidence for a specific role of G-CSF in the treatment of AML with t(8;21), namely in patients who are not eligible for aggressive chemotherapy.