Epithelial Membrane Antigen may be used as a supplement marker to CKs for detection of epithelial differentiation, especially in sarcomatoid carcinoma or those undifferentiated carcinomas that are negative or only focally positive for CKs. Epithelial membrane antigen is not entirely specific for carcinomas. Every eligible specimen diagnosed as undifferentiated malignant tumors, poorly differentiated malignant tumours and small round cell tumours in histopathology received for immunohistochemistry in IHC LAB, Department of pathology, SMS Medical college and Hospital, Jaipur. Total out of 92 cases, most frequent diagnosis was mesenchymal followed by epithelial, hematopoietic and germ cell tumours.