Karyotyping makes it possible to stratify outcomes in acute myeloid leukemia (AML) patients. Previous studies have suggested that the presence of cells with normal metaphases negatively affects prognosis in patients with core-binding factor AML, especially in patients with inv(16), whereas no difference was noted for patients with t(8;21)(q22;q22). In the present study, we determined the influence of residual normal metaphases in 106 patients with AML patients with t(8;21)(q22;q22). The presence and total number of normal and abnormal metaphases were tallied for patients with AML patients with t(8;21)(q22;q22). There was no significant impact on complete remission rate between patients with one or more normal metaphases versus those with no normal metaphases (88.4 vs. 83.8 %, P = 0.503), whereas patients with one or more normal metaphases were noted to have a significantly worse 3-year overall survival than patients without normal metaphases (32 vs. 55 %, P = 0.017). Overall, these results suggest that the presence of cells with normal metaphases negatively affected the prognosis in AML patients with t(8;21).