Introduction: Evolution of cytopathology in the past few decades as a distinct adjunct in screening and diagnosis of a neoplastic process, has paralleled the development of newer ancillary techniques like immunocytochemistry, flow cytometry, karyotyping and genetic studies. But a combination of LM and IHC will not identify every tumor and some diagnostic problems go unanswered. If the differential diagnosis on routine LM includes a tumor that is known to possess distinctive ultra structure, Electron Microscopy (EM) is clearly the method to select for confirmation as a subsidiary technique. Aim: Owing to the restricted availability of TEM in most centres, data pertaining to its utility in tumor cytopathology is limited. Hence, the current study is designed to study the role of Electron Microscopy (EM) in fine needle aspiration cytological examination of neoplastic lesions, to correlate the findings of EM with Light microscopic findings and to correlate the EM findings with immunohistochemical findings, wherever possible. Materials and Methods: Electron microscopy was carried out in a total of 50 cases where were subjected to FNAC for suspected neoplastic primary malignant or metastatic lesions. The cellular features of material aspirated were studied and ultrastructural details of cytoplasm including the plasma membranes, organelles and nuclear features were noted. The cases were grouped histogenetically and analysed. The final cytological diagnosis were tabulated and compared with the histopathological diagnosis.