OBJECTIVES.: The utility of hormone therapy in the management of uterine sarcomas is poorly defined. We hypothesize that estrogen receptor (ER) expression is common in uterine sarcomas, and carries prognostic significance. Further, we hypothesize that ER-positive uterine sarcomas respond to hormone therapy. METHODS.: We retrospectively reviewed charts of patients with uterine sarcomas. Stepwise Cox proportional hazards regression model was used to evaluate variables related to the risk of death: age, histology, stage, use of pelvic radiotherapy, and ER expression. In addition, we examined clinical outcomes in patients treated with aromatase inhibitors, megestrol acetate, depot medroxyprogesterone acetate, and tamoxifen. RESULTS.: Fifty-four patients underwent immunohistochemical staining, and 34 (63%) were ER-positive. Kaplan-Meier survival analysis and log-rank test indicated that patients with ER-positive sarcomas demonstrated improved overall survival when compared with ER-negative patients (median OS 36 vs. 16 months, p=0.004). Upon multivariate analysis, ER positivity retained significance as an independent predictor of survival (HR=0.32, CI 0.12-0.89, p=0.03). Four patients received hormonal treatment in the adjuvant setting and remained in remission (range of follow up: 18-68 months). Eighteen patients received hormone therapy in the setting of recurrent or progressive disease: fourteen (78%) demonstrated stable disease or complete or partial response (range of follow up: 6-124 months). CONCLUSIONS.: ER expression is common and is associated with improved overall survival in uterine sarcomas. Conducting immunohistochemical staining to ascertain ER status may aid with prognostication in this disease. Hormone therapy should be considered in patients with primary and recurrent ER-positive uterine sarcomas.