We report a rare case of endometrial adenocarcinoma involving both horns of a bicornuate uterus in a postmenopausal woman. Patient underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy and bilateral pelvic lymph node dissection following an initial positive diagnosis of well differentiated endometrioid adenocarcinoma on endometrial biopsy. Incidentally, the left ovary revealed a well differentiated sertoli leydig cell tumor. Endometrial carcinoma arising in malformed uterus is rare. Its simultaneous occurrence with an ovarian sertoli leydig cell tumor has not been reported in English literature so far. This case is reported for its rarity.