Objective: To report the comparative effect of combined medroxyprogesterone acetate (MPA) and external beam pelvic radiotherapy (EBRT) with EBRT alone on local or distant recurrences, overall survival and treatment related toxicities in patients with stage Ic grade 3 endometrial cancer. Methods:A retrospective review of 80 International Federation of Gynecology and Obstetrics (FIGO) stage Ic grade 3 endometrial carcinoma patients treated between October 1994 and October 2004 at Renmin Hospital, Wuhan University, China was performed. All patients underwent surgery, of which 40 patients in arm Ⅰ received combined MPA and EBRT while in arm Ⅱ 40 patients received only adjuvant EBRT after surgery. The median dose of EBRT in arm Ⅰ was 50 Gy (range 36-54 Gy) and in arm Ⅱ was 45.2 Gy (range 43.2-50.4 Gy). Multivariate analysis was performed for the prognostic factors and Kaplan-Meier method was used for overall survival. Results: Of the 80 eligible patients, 40 in each group could be evaluated. The follow-up times ranged from 4-98 months with a median of 45 months. The overall survival rates at five years were 73% among patients treated with combined MPA and EBRT and 28.2% among patients treated with EBRT alone (P < 0.001). The rate of distant metastasis was significantly higher among patients treated with EBRT alone group than combined MPA and EBRT (55% vs 25%, P = 0.006) while no difference in Ioco regional recurrence rates was observed in both treatment groups. Most of the side effects observed in the combined MPA and EBRT group. Age (P < 0.001) and the presence of progesterone receptors (P = 0.003) were independent significant prognostic factors for overall survival in multiple regression analysis. Conclusion: We has been concluded that the addition of progestagen to external beam pelvic radiotherapy significantly improved survival and reduced distant metastasis among women with stage Ic grade 3 endometrial cancer.