['Unfavorable histology endometrial carcinomas confer worse prognosis. We determined the association of adjuvant radiation on local recurrence and survival for unfavorable, early stage endometrial cancer.', 'We retrospectively identified 125 patients who had a hysterectomy for early stage (FIGO IA), unfavorable histology (clear cell, papillary serous or grade 3 endometrioid), endometrial carcinoma treated between 1992 and 2011. Patients were restaged according to current FIGO 2009 guidelines. Primary endpoint was local control and secondary endpoints were distant recurrence and overall survival.', 'The median age of the cohort was 67 years old with a mean follow up 152 months. Adjuvant radiation was delivered in 60 patients (48%). There were a total of 24 recurrences; 5 had local-regional recurrences, 4 local and distant recurrence, 12 distant only recurrences, and 3 had unspecified recurrences. The 5-year local-regional control was 97.8% in patients who received radiation and 80.1% in patients who did not receive radiation (p=0.018). The 5-year overall survival rate was 68.1% if patients did not receive radiation and 84.9% if they did receive radiation (p=0.0062). On univariate analysis, only radiation (HR 0.12, 95% CI: 0.03 to 0.49, p-value=0.018) was associated with a significant increase in local relapse free survival.'] Is adjuvant radiation in early stage , unfavorable histology endometrial carcinoma associated with improved local control and survival?