Background: Pancytopenia is a common problem in clinical practice. Pancytopenia is defined as Hemoglobin less than 10 g/dL, total leucocyte counts less than 4,000/dL and platelet count less than 1.5 lakhs/dL. Causes of pancytopenia vary from nutritional deficiencies, bone marrow failure status and malignancies. Pancytopenia is a common problem in geriatric population also. In this study, we try to find common causes of pancytopenia in geriatric population in a tertiary care hospital. Objectives: To study the clinic-aetiological profile of pancytopenia in elderly population in a tertiary care hospital. Methods: 100 patients who are more than 60 years of age attending General Medicine Outpatient Department were included in the study. Diagnosed cases of any malignancies and Patients on chemotherapy were excluded from the study. These patients were subjected to detailed history taking and clinical examination. Routine investigations like complete blood count, peripheral smear, reticulocyte count, Coombs test, serum cobalamin level’s renal function tests and liver function tests were done. Bone marrow examination was done in cases where indicated. Upper gastrointestinal endoscopy was done in cases wherever indicated. Result: Out of 100 patients included in the study ,73 were males and 27 were females. 63% of Patients were below 65 years and 37% of patients were above 65 years. The mean age of the patients were 64.9 .Fatigue was the most common symptom (73%).Followed by paraesthesia (28%) ,Fever (19%) ,Weight loss (20%) and Bleeding (9%) .Most common cause of pancytopenia was cobalamin deficiency (62%) .Other causes were MDS(12%) Disseminated TB (9%) ,HIV (5%) ,Chronic liver disease (5%), Acute promyelocytic leukemia (3%), Aplastic anemia (2%), Hairy cell leukemia (1%) and SLE (1%).Conclusion: Vitamin B12 deficiency is the most common cause of pancytopenia in elderly population Symptoms of Vitamin B12 deficiency may be non specific in elderly. High index of suspicion is required for the diagnosis. Mean corpuscular volume may not be highly elevated in all patients. Hence all patients in geriatric population presenting with pancytopenia should be tested for Serum Vitamin B12 levels.