The optimal treatment of eosinophilic leukemia is still uncertain. We report the successful treatment of a 21-year-old patient with eosinophilic leukemia, without cytogenetic abnormalities, by bone marrow transplantation from an unrelated donor. The conditioning regimen for the transplantation consisted of fractionated total body irradiation and cyclophosphamide. Acute GVHD, grade I, post-transplantation was successfully treated. No other severe complications occured. The patient is alive in complete remission 21 months after unrelated bone marrow transplantation.