We present a 23-year-old man with chronic neutrophilic leukemia (CNL). Physical examination revealed hepatosplenomegaly. Leukocytosis was evident with predominance of mature neutrophils with basophilic granules. Bone marrow aspiration revealed mature myeloid hyperplasia. Congenital Robertsonian translocation [45,XY,der(13;22)(q10;q10), in all of analyzed 20 cells] was detected; however, cytogenetic and molecular studies for 9:22 translocation were negative. He was diagnosed with CNL and hydroxyurea was started to control his symptoms and white blood cell count. He was then successfully treated with allogeneic bone marrow transplantation (BMT). Although the prognosis of CNL was not determined, curative therapy including allogeneic hematopoietic stem cell transplantation should be attempted in young patients with CNL.