Brenner tumors are rare ovarian tumors accounting for 2-3% of all ovarian neoplasms. These tumors are commonly seen in fourth to fifth decade. They are classified as benign, borderline and malignant. These tumors are associated with estrogen production, thus altering the estrogen-progesterone ratio. This high estrogen stimulates the endometrium and is responsible for producing endometrial hyperplasia, atypia and carcinoma. A rare case report is being presented here of Type l endometrial carcinoma-Grade 3 stage lllc associated with benign Brenner tumor of ovary in a 65 year old postmenopausal women.