Objectives: To compare overall survival (OS) in women with endometrial cancer who received hysterectomies with and without oophorectomies. Methods: Data were obtained from the Surveillance, Epidemiology, and End Results Program (SEER) Research Plus dataset. The sample included endometrial cancer women aged 18 and above diagnosed between 2014 to 2018 (n=52,680) who had hysterectomies with oophorectomies (ovary removed) and without oophorectomies (ovary retained). Histology of endometrial cancer included low-grade and high-grade endometrioid carcinoma, papillary serous carcinoma, clear cell carcinoma, carcinosarcoma, and mixed type. Kaplan-Meier curves, log-rank comparisons, and Cox regression analyses were used to evaluate OS. Results: There were 97.4% patients (n=51,324) who had oophorectomies while 2.6% (n=1,356) did not. Mean age was 62.7 years; the majority were White (79.6%, n=41,941), stage I (78.8%, n=41,496), and endometrioid type (78.1%, n=41,142). Adjuvant therapies were radiation (28.3%, n=14,893), chemotherapy (22.6%, n=11,930), and combined radiation/chemotherapy (12.5%, n=6,598). There were 5,051 deaths (9.6%) among which 119 deaths (0.2%) were in the ovary retained group while 4,943 deaths (9.4%) were in the ovary removed group. In the whole sample, OS did not differ between the two groups (p=0.14). In those with late-stage endometrial cancer (stages III and IV), there were lower hazards for OS (HR:0.75, 95% CI: 0.58-0.97, p=0.03) in the ovary removed group. In those with early-stage endometrial cancer (stages I and II), the OS did not differ between the two groups (p=0.21). Conclusions: Oophorectomy in late-stage endometrial cancer patients who received hysterectomy was associated with improved OS. However, oophorectomy in early-stage endometrial cancer patients was not associated with improved OS. Fertility-sparing surgery may be considered for those in early-stage endometrial cancer who desire to preserve ovary function. Further studies are needed to confirm when oophorectomy is indicated in endometrial cancer patients with ovarian activity. Objectives: To compare overall survival (OS) in women with endometrial cancer who received hysterectomies with and without oophorectomies. Methods: Data were obtained from the Surveillance, Epidemiology, and End Results Program (SEER) Research Plus dataset. The sample included endometrial cancer women aged 18 and above diagnosed between 2014 to 2018 (n=52,680) who had hysterectomies with oophorectomies (ovary removed) and without oophorectomies (ovary retained). Histology of endometrial cancer included low-grade and high-grade endometrioid carcinoma, papillary serous carcinoma, clear cell carcinoma, carcinosarcoma, and mixed type. Kaplan-Meier curves, log-rank comparisons, and Cox regression analyses were used to evaluate OS. Results: There were 97.4% patients (n=51,324) who had oophorectomies while 2.6% (n=1,356) did not. Mean age was 62.7 years; the majority were White (79.6%, n=41,941), stage I (78.8%, n=41,496), and endometrioid type (78.1%, n=41,142). Adjuvant therapies were radiation (28.3%, n=14,893), chemotherapy (22.6%, n=11,930), and combined radiation/chemotherapy (12.5%, n=6,598). There were 5,051 deaths (9.6%) among which 119 deaths (0.2%) were in the ovary retained group while 4,943 deaths (9.4%) were in the ovary removed group. In the whole sample, OS did not differ between the two groups (p=0.14). In those with late-stage endometrial cancer (stages III and IV), there were lower hazards for OS (HR:0.75, 95% CI: 0.58-0.97, p=0.03) in the ovary removed group. In those with early-stage endometrial cancer (stages I and II), the OS did not differ between the two groups (p=0.21). Conclusions: Oophorectomy in late-stage endometrial cancer patients who received hysterectomy was associated with improved OS. However, oophorectomy in early-stage endometrial cancer patients was not associated with improved OS. Fertility-sparing surgery may be considered for those in early-stage endometrial cancer who desire to preserve ovary function. Further studies are needed to confirm when oophorectomy is indicated in endometrial cancer patients with ovarian activity.