Background: Pancytopenia is a hematological entity characterized by anemia, leucopenia and thrombocytopenia simultaneously. The causes of pancytopenia are diverse. The spectrum of different etiologies leading to pancytopenia vary globally, as well as within different geographical regions of the same country like India. Aims and objectives: To assess the etiological profile of Pancytopenia on the Basis of hemato–serological and Bone Marrow Studies in western Rajasthan, India. Material and Methods: This was a cross–sectional observational study which includes randomly selected 120 patients of Pancytopenia. The patients were selected from the medical outpatient and indoor of M.D.M. Hospital, Dr S.N. Medical College, Jodhpur. Results: Out of 120 cases analysed, 63 patients were male and 57 patients were female. Megaloblastic anemia (66.67%) was the most common cause of pancytopenia. The next common cause were acute Leukemias(14.16%),Hypersplenism(5.00%), Aplastic Anemia(3.33%), secondary to systemic infections(3.33%), Myelodysplastic Syndrome(3.33%), Myelofibrosis(1.66%), chronic myeloid leukemia(0.83%), PNH(0.83%), and SLE(0.83%). Conclusion: Megaloblastic anemia is commonest cause of pancytopenia, followed by acute leukaemia and aplastic anemia.