Many studies describe an association between Epstein-Barr virus and lymphoproliferative disorders, especially lymphomas and acute lymphoblastic leukemia (ALL). Because of the delay or lack of adequate in immune response among these patients, serologic tests can lead to false-negative results. Real-time PCR testing of patients being admitted with lymphoproliferative disorders, especially those diagnosed as ALL and lymphomas, is useful during follow-up and treatment. Introduction: Epstein-Barr virus (EBV) is associated with different types of human malignancies, including Burkitt lymphoma, nasopharyngeal carcinoma, and lymphomas. We retrospectively investigated the presence of EBV-DNA by real-time PCR in clinical samples of patients diagnosed as having hematologic malignancies while investigating the cause of lymphoproliferative disorders, and investigated its relationship to clinical manifestations. Patients and Methods: Fifty clinical samples sent to Gazi University's hematology clinics between November 2013 and March 2018 were included. EBV-DNA was investigated by real-time PCR method, and EBV-IgM and EBV-IgG antibodies were investigated by ELISA. Results: Fifty serum samples were investigated, and 10% (5/50) EBV-DNA positivity was determined in patients. Of the 5 patients with EBV-DNA positivity, 2 had acute lymphoblastic leukemia, 1 lymphoma, 1 T-cell lymphoma, and 1 B-cell lymphoma. Concomitant EBV-DNA and viral capsid antigen (VCA)-IgM positivity was not detected. The VCA-lgM test results of the all EBV-DNA-positive patients were negative and VCA-IgG positive (except for 1 patient). Regarding virus load, of the 5 samples, 2, 1, 1, and 1 of the samples had a virus load of 10(2), 10(3), 10(4), and 10(5) copies/mL, respectively. Conclusion: EBV infection is threatening in patients with hematologic malignancies and are diagnosed by serologic and molecular methods. As a result of the study, we suggest that the detection of EBV-DNA by real-time PCR in patients being admitted with lymphoproliferative diseases and diagnosed as acute lymphoblastic leukemia and lymphomas may be useful in follow-up and treatment. (C) 2021 Elsevier Inc. All rights reserved.