Granulocytic sarcoma is a localized tumor composed of immature cells of the granulocytic series. Most granulocytic sarcomas occur in the course of acute leukemia and the blast crisis of chronic leukemia. Rarely, however, it may present before leukemia becomes clinically apparent. It may also occur in patients with myeloproliferative disorders. It has been reported that it occurs in 3% to 9% of patients with acute myelogenous leukemia (AML) and the incidence of granulocytic sarcoma is reported to be higher in patients with t (8;21). However, epidural granulocytic sarcoma associated with t (8;21) is very rare. In this report, we describe a patient with AML associated with t (8;21) in whom the cord compression occurred due to epidural granulocytic sarcoma. In addition, this case present infiltration of both pleura by blast cells. She was treated with local irradiation and chemotherapy successfully.