Endometrial cancer is one of the most common female malignancies in the United States, and has increased in incidence in Taiwan in recent decades.A recent population-based analysis noted that 4% of endometrial cancers occurred in women aged 40 years or younger, furthermore it is up to 15% in Taiwan according to the data of cancer registry. The standard treatment of endometrial cancer results in surgical menopause and places patients at risk for the long-term sequelae of estrogen deprivation. The goal of this study was to determine the frequency of a coexisting ovarian malignancy and to evaluate the outcome of ovarian preservation in women with treatment for endometrial cancer.