The endometrioid carcinoma is a primary neoplasm of the ovary which on light and electron microscopy, closely resembles adenocarcinoma of the uterine endometrium. It is one of the common ovarian carcinoma, but frequently diagnosed as unclassified adenocarcinoma or other types of adenocarcinoma due to histological variabilties of the tumor. The mesodermal mixed tumor of the ovary is a combined epithelial and mesenchymal neoplasm containing heterologous elements. This tumor is closely related with carcinosarcomas having homologous mesenchymal elements but differential diagnosis must be done due to better prognosis in carcinosarcoma. Histogenesis of endometrioid carcinoma and mesodermal mixed tumor are controversial but at present, most pathologists believe that these tumors are considered to originate from ovarian endometriosis, Mullerian or surface epithelium of the ovary. According to WHO classification, these tumors are categorized in malignant endometrioid tumors of the ovary. We report two cases of endometrioid carcinoma and one case of mesodermal mixed tumor of the ovary.