Objectives: To evaluate the synchronous gynecologic cancers in Turkish women. Materials and methods: A population-based longitudinal cohort study was conducted using Izmir Cancer Registry (ICR) data on gynecologic cancer patients diagnosed in the period 1993 to 2005. The registry covers the 3.7 million population of Izmir and has been collecting data on cancer incidence and survival of cancer patients' since 1992. The ICR collects data on all new cases of cancer from all the hospitals (n = 22) in the city. Results: A total of 4,185 women were identified with gynecologic cancer between 1993 and 2005, 1,526 with endometrial, 1,206 with cervical, 1,198 with ovarian, 115 with vulvar, 67 with other uterine (sarcoma etc.), 33 with vaginal and 40 with other gynecologic cancers (tuba uterina etc.). Fifty-five (1.3%) patients with invasive synchronous primary cancers were identified, 43 of these tumor pairs being endometrium-ovaries (81%), 66 of all lesions being endometrioid adenocarcinomas. Conclusions: Independent primary tumors of the endometrium and ovary are the most commonly encountered synchronous tumors of the female genital tractus with endometrioid adenocarcinoma as the most frequent component.