Synchronous primary cancers of the endometrium and ovary are found in 5% of women with endometrial cancer and 10% of women with ovarian cancer. In the present case, a multigravid 46-year-old woman complained of lower abdominal pain and abdominal distension. She did not define abnormal uterine bleeding. Screening ultrasound revealed a papillary containing structure, irregular, cystic 16 x 15 x 10 cm right ovarian mass. Preoperative endometrial biopsy revealed endometrioid adenocarcinoma. Ascites sampling, radical hysterectomy, bilateral salpingo-oophorectomy, pelvic and paraaortic lymphadenectomy, omentectomy, appendectomy and cytologic sampling of the undersurface of the diaphragm were carried out. Intraoperative and histological examinations showed Stage RIC papillary serous carcinoma and stage IC endometrioid adenocarcinoma. Synchronous genital tract neoplasms constitute a more common clinical problem than would generally be expected.