INTRODUCTON: The aim of this study was to evaluate the clinical characteristics, post-surgery adjuvant treatment approach and posttreatment disease course in patients with intermediate risk stage I endometrium cancer and also to assess the effects of known prognostic factors on this group of patients. PATIENTS AND METHODS: A total of 148 patients followed up postoperatively or after adjuvant treatment between 1996 and 2007 were evaluated retrospectively. Median follow-up duration was 67 months (range: 7-166). Among the study population 14.9% had Ib and 83.1% had stage Ic disease. 72 were treated by external beam radiotherapy (EBRT), 7 by intracavitary radiotherapy (ICRT), 65 by external + intracavitary radiotherapy (EBRT + ICRT), and one by chemoradiotherapy (CRT). RESULTS: Vaginal vault is found to be the most common site of recurrences. Five and 10-year local control (LC) rates were 96.6% and 95.9%, respectively, while 5 and 10-year distant control (DC) rates were 94.6% and 91.9%, respectively. One, 5 and 10-year overall survival rates (OS) were 99.3%, 87.6% and 71.2%, respectively, while 1, 5 and 10-year progression-free survival rates (PFS) were 97.3%, 87.6% and 71.2%, respectively. Univariate analysis has revealed that prognostic factors as age (P = 0.0001), menopausal status (P = 0.049) and EBRT duration (P = 0.003) statistically significantly affected OS; while age (P = 0.0001) and EBRT duration (P = 0.006) affected PFS. Multivariate analysis has revealed that only age (P = 0.001) (P = 0.0001) and ERT duration (P = 0.021) (P = 0.027) affected both OS and PFS. CONCLUSION: LC and OS rates are high in the intermediate risk group. Age over 60 years and EBRT duration of 35 days and over both have negative effects on outcome in this group.