Blastic natural killer (NK)-cell leukemia/lymphoma is a neoplasm of NK origin with aggressive behavior. The disease affects mainly elderly people and often presents with skin lesions and overt leukemia. Blastic morphology, an NK-cell immunophenotype, and lack of association with Epstein-Barr virus are the clues for the diagnosis. We report herein, the case of a patient with a blastic NK-cell leukemia/lymphoma with overt leukemia at diagnosis, who achieved a complete response after CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) chemotherapy. However, the patient relapsed a few months later and died due to disease progression. Cases of blastic NK-cell leukemia/ lymphoma previously reported are briefly reviewed.