Introduction: Little observational data exists regarding the efficacy of different treatment modalities on the survival outcome of patients with uterine leiomyosarcoma. Objective and Design: This is a retrospective cohort study using the Surveillance, Epidemiology, and End Results database to identify surgery-based treated patients with uterine leiomyosarcoma diagnosed between 1982 to 2015 (N = 4289). The associations between survival outcomes and treatment modalities regarding postoperative radiation and ovarian conservation were assessed. Results: A total of 1104 patients were included in the study, 19.02% (210/1104) patients received postoperative radiation, 11.59% (128/110) patients received ovarian conservation. The median follow-up duration was 37.27 ± 34.69 months (95%CI: 35.39-39.38 months). After propensity score matching, there were no variable differences among compared groups. For FIGO stage I-II patients, postoperative radiation did not improve five-year-overall survival (49.1 vs. 47.1%, p = 0.818) and five-year-cause-specific survival (51.5 vs. 49.9%, p = 0.910). For International Federation of Gynecology and Obstetrics stage I patients who were younger than 50 years old, five-year-overall survival (75.4 vs. 60.3%, p = 0.053) and five-year-cause-specific survival (75.4 vs. 65.1%, p = 0.146) were similar between women underwent ovarian conservation and those who did not. However, after excluding patients who received radiotherapy, patients showed a better survival outcome than control group (five-year-overall survival: 76.3 vs. 54.0%, p = 0.031; five-year-cause-specific survival: 76.30 vs. 55.3%, p = 0.046). Conclusions: In women with stage I-II uterine leiomyosarcoma, postoperative radiation did not improve five-year-overall-survival and five-year-cause-specific survival. In young women with stage I uterine leiomyosarcoma who didn’t receive postoperative radiotherapy, ovarian conservation was associated with increased overall survival and cause-specific survival.