The authors report a case of nasal-type natural killer/T (NK/T)-cell lymphoma in a 15 years old girl, with rapid fatal evolution. NK/T proliferations are very rare and only a few cases have been described in children, most of them NK/T-cell lymphoma or leukemia, but not nasal-type NK/T-cell lymphoma. Clinical and biologic characteristics of these diseases are discussed with focus on their aggressivity and poor response to conventional chemotherapy.