Background: Chronic lymphocytic leukaemia (CLL) is a set of chronic lymphoproliferative disorder which is characterized by abnormal monoclonal proliferation of mature appearing lymphocytes. CLL/SLL represents approximately 20% of all and is the most common type of leukaemia in the western world in B–cell malignancies. Aim: To evaluate various haematological parameters in peripheral blood, bone marrow and immunophenotyping. Method: This study was conducted in the Department of Pathology, Government Medical College and Hospital, Chandigarh. Clinical and laboratory characteristics of fifteen treatment naive CLL cases were studied. Bone marrow examination and flow cytometric immunophenotyping were performed in all patients to confirm the diagnosis. The prognostic factors such as RAI staging, CD38, ZAP70 were correlated. Results: Nine out of 15 cases (60%) were males and 6 (40%) were females, age ranged between 50–70 years with most common presenting complaint of generalized weakness. Mean Hb was 10.8 ± 2.9 g/dl and ranged from 6.3–14.5g/dl and the median smudge cell percentage was 4% and ranged from (2–43%). The most common pattern in bone marrow was diffuse. Maximum cases were in RAI stage III. No significant correlation found between the clinical stage of CLL and CD38 and ZAP70 markers.