Hairy cell leukemia variant (HCLv) is a rare B-cell chronic lymphoproliferative disorder with features of the classic HCL but presenting some particularities, a poor response to conventional therapy of classic HCL and a more aggressive course of disease with shorter survival than classic HCL. We present a case of a 52-year-old man hospitalized in July 2012 in the Clinic of Hematology of Craiova, Romania, having splenomegaly, leukocytosis with lymphocytosis, anemia and thrombocytopenia, without monocytopenia, which exposed, in the peripheral blood and bone marrow cells, intermediate morphology between hairy cells and prolymphocytes and immunophenotype of mature B-cell phenotype CD19, CD20, CD22, CD11c, CD103, low positive for CD25 and negative for CD3, diagnosed with HCL variant, with no response to conventional chemotherapy and interferon-alpha, an aggressive course of disease and a survival of less than a year from diagnosis.