It is still unclear what the best adjuvant treatment for uterine leiomyosarcoma (uLMS) is. Researchers assessed the rate at which stage II and stage III uLMS patients received adjuvant chemotherapy and radiation therapy, and they investigated whether or not such treatment was associated with improved survival. In this study, patients with stage II or III uLMS who were treated between 2004 and 2016 were retrieved from the National Cancer Database. Predictors of receiving adjuvant chemotherapy or radiation therapy were estimated using multivariate regression models. The inverse probability of treatment weighted (IPTW) propensity score approach was used to account for observed confounders, and radiation therapy receipt was adjusted in the outcome model to examine the effect of chemotherapy on all-cause mortality. The effect of radiation therapy on all-cause mortality was assessed using an IPTW propensity score technique and controlling for the receipt of adjuvant chemotherapy. In total, 890 patients were found. The percentage of patients who received adjuvant chemotherapy rose from 62.2% in 2010 to 70.4% in 2016, while the percentage of patients who received radiation therapy fell from 26.7% in 2010 to 10.4% in 2016. A lower proportion of patients with stage III (compared to stage II) illness received radiation treatment. Patients in stage III had a 30% lower risk of all-cause mortality when treated with chemotherapy after propensity score weighting (HR 0.70, 95% CI 0.45-0.98), while patients in stage II did not affect mortality (HR 0.93, 95% CI 0.70-1.20). Compared to patients without radiation therapy, those with stage II tumors had a 26% lower risk of mortality (HR 0.74; 95% CI, 0.53-0.99), and those with stage III disease had a 57% lower risk of mortality (HR 0.43; 95% CI, 0.18-.99). Women with stages II and III uLMS are increasingly receiving chemotherapy and receiving less radiation therapy. While there was no correlation between the use of adjuvant chemotherapy and survival in stage II patients, individuals who received radiation therapy had much better outcomes than those who did not.