Pancytopenia is defined by reduction of all the three formed elements of blood below the normal reference. It may be a manifestation of a wide variety of disorders, which primarily or secondarily affect the bone marrow. Haematological investigation forms the bedrock in the management of patients with pancytopenia and therefore needs detailed study. The total number of cases studied were 100 over a period of two years in the department of pathology, JSS Hospital, Mysore. Megaloblastic anaemia (33%) was the commonest cause of pancytopenia. Other causes were nutritional anaemia (16%), aplastic anaemia (14%), hypersplenism (10%), sepsis (9%) and leukaemia (5%). Less common causes were alcoholic liver disease, haemolytic anaemia, HIV, dengue, systemic lupus erythematosus, viral hepatitis, disseminated TB and multiple myeloma. Most of the patients were in the age group of 11-30 years with a male:female ratio of 1.6:1.Generalised weakness and fatigue (88%) were the commonest presenting complaints. Haemoglobin level varied from 1-10 g/dl with majorIty (70%) of them in the range of 5.1-10 g/dI. TLC was in the range of 500-4000 cells/cmm. Most (34%) of them had 3100-4000 cells/cmm. Platelet count was in the range of 4000-1,40,000 cells/cmm. Reticulocyte count varied from 0.1%-15% with majority (82%) of them ranging from 0.1%-2%. The bone marrow cellularity was hypocellular in 14%, hypercellular in 75%, and normocellular in 11% of the patients. Pancytopenia is a relatively common entity with inadequate attention in Indian subcontinent. A comprehensive clinical and haematological study of patients with pancytopenia will usually help in the identification of the underlying cause. However in view of wide array of aetiologies, pancytopenia continues to be a diagnostic challenge for haematologists.