AbstractBackground: Chronic lymphocytic leukemia is a malig-nancy of CD5+ B cells that is characterized by the accumulationof small, mature-appearing neoplastic lymphocytes in theblood, bone marrow and secondary lymphoid tissues, resultingin lymphocytosis, leukemic cell infiltration of the bone marrow,lymphadenopathy and splenomegaly.Aim of Study: Our objective was to analyse clinical,haematological, immunophenotypic and cytogenetic profilesof Chronic Lymhocytic Leukemia (CLL) in Egypt.Patients and Methods: This retrospective study involvedone hundred and twenty adult CLL patients diagnosed accord-ing to International Workshop on Chronic LymphocyticLeukemia (IW-CLL) from January 2011 to December 2019.Data were collected and statistically analysed.Results: Chronic lymphocytic leukemia is a disease ofelderly and may have an association hepatitis C virus. Thestudy showed that mean of age of CLL patients was 61.03 (±9.9), 42 (35%) of patients were positive for hepatitis Cantibody.Conclusion: Chronic lymphocytic leukemia is adiseaseof elderly, there may be an association between hepatitis Cvirus and development of chronic lymphocytic leukemia.