Abstract Introduction: Bone marrow examination plays an important role in diagnosis of haematological as well as non-haematological disorders. It is one of the diagnostic investigations of cases of Pyrexia of unknown origin, cytopenia, abnormal red cell indices, malignant haematological disorder and suspected bone marrow metastasis as its leads to an etiological diagnosis in most of the cases. BMA is mainly performed for cytomorphological examination. Aim: The aim was to study the Clinico-morphological spectrum of bone marrow aspiration and Biopsy examination and its correlation with biochemical parameters;and to assess the diagnostic value of bone-marrow examination. Material and methods: It is an observational study with retrospective and prospective design. The study was conducted at in Department of Pathology, Heritage Institute of Medical Sciences, Varanasi. All eligible participants age group 3 month to 85 years were included. Data collection was done from November 2018 to April 2022. Bone marrow examination was performed for all cases. The parameters assessed after bone marrow examination were cellularity, myeloid to erythroid ratio, cytomorphological details of all cell lineage. Results: In present study, commonest indication of bone marrow examination was unexplained anaemia followed by cytopenia and malignant haematological disorder. Distribution of bone marrow cellularity was normocellular in most of the cases. Dimorphic anaemia (26.21%) was most common finding followed by Micro normoblastic picture (22.33%) & Megaloblastic changes in 18.45% cases. Other finding was Acute leukaemia in which AML was most common finding. Conclusion: Bone marrow study reproducible procedure used for the evolution of Haematological and non-haematological condition. Various studies shows the BME is an essential investigation for the diagnosis and management of many disorders of blood and BM.