Relatively few cases of Epstein-Barr (EBV)-positive B-cell lymphomas arising in patients with angioimmunoblastic T-cell lymphoma (AITL) have been reported. We report a case of AITL in which diffuse large B-cell lymphoma arose 13 months after the initial diagnosis of AITL. In a 36-year-old female patient, evaluated for moderate leukocytosis, peripheral and abdominal lymphadenopathy AITL was diagnosed in March 2008, based on results of fine-needle aspiration cytology (FNAC) of the enlarged cervical and supraclavicular lymph nodes.The diagnosis was also confirmed by immunophenotyping and histopathology of the cervical lymph nodes. The patient initially recieved FED chemotherapy (fludarabine, cyclophosphamide, dexamethasone) followed by elective autologous hematopoietic stem cell transplantation. In April 2009 the patient was hospitalized because of fever, pancytopenia, hyperbilirubinemia and peripheral lymphadenopathy. The FNAC of the enlarged cervical lymph nodes was performed again, but this time the smears were composed of polymorphous population of lymphocytes with the predomination of large cells, CD20+ on immunocytochemical stains. The immunophenotyping confirmed a predomination of monoclonal mature B-cells. Patient had high number of EBV DNA copies in plasma and serologic testing revealed increased titers of EBV VCA IgG and EBV EBNA IgG. CHOP-R chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone and rituximab) was then administered, resulting in good partial response of the disease. Reduced intensity allogeneic stem cell transplantation performed thereafter, resulted in complete remission of the disease. AITL is a rare lymphoproliferative disorder in which the neoplastic T-cells represent the minority of the lymph node cell population and almost all cases harbor EBV-infected B-cells. Various authors postulated that immunodeficiency in AITL patients together with immunosupresive effects of cytotoxic drugs, may be responsible for EBV-induced proliferation of latently or newely EBV-infected B-cells with eventual clonal selection and progression to aggressive B-cell lymphoma.