Endometrial carcinoma frequently presents in the elderly, in which comorbidities may restrict surgical management. For this small subset, definitive radiotherapy, frequently incorporating brachytherapy (BT), has been reported with acceptable outcomes. A National Cancer Data Base (NCDB) analysis was conducted to more extensively evaluate radiotherapy practice patterns and the impact of treatment modality. The NCDB was queried for patients with biopsy-proven FIGO stage I endometrioid adenocarcinoma from 1998-2006 treated with radiotherapy. Excluded patients included those with inadequate follow-up or surgical management aside from biopsy alone. Factors associated with BT utilization were established using Chi-square test and multivariate logistic regression with forward conditional selection. Log rank and Cox proportional hazards modeling were used to assess variables associated with survival. Eight hundred and fifty three patients met inclusion criteria, of whom 23.7%, 31.3% and 45.0% received BT alone, external beam radiotherapy (EBRT) and BT, or EBRT alone, respectively. BT utilization as monotherapy remained stable over time, varying from 19.2-33.6% patients/year (p=0.32). On multivariate analysis, use of BT alone was lower in patients with more advanced age (≥80 years; OR 0.50, 95% CI 0.31-0.80, p<0.01) and high grade disease (poorly differentiated; OR 0.47, 95% CI 0.26-0.84, p=0.01). Among patients who received any BT, technique was specified in 42.7% of cases with 83.5% and 16.5% receiving HDR and LDR, respectively. Among those receiving EBRT alone, 9.4% received palliative EBRT (≤30 Gy) and 90.6% received doses >30 Gy. With a median follow-up of 36 months (range, 1-170), the unadjusted median survival for palliative EBRT, high-dose EBRT alone (>30 Gy), BT alone, and EBRT+BT was 12.1 months, 31.5 months, 44.6 months and 57.1 months, respectively (p<0.01). After correcting for significant factors from log rank analysis which included Charlson-Deyo comorbidity score, age and grade, a higher risk of mortality was seen in those treated with palliative EBRT (HR 2.75, 95% CI 1.66-4.55, p<0.01) and high-dose EBRT alone (HR 1.43, 95% CI 1.07-1.91, p=0.02) compared to EBRT+BT. No significant survival difference was seen using BT alone (HR 1.29, 95% CI 0.92-1.79, p=0.14) compared to EBRT+BT. Brachytherapy utilization, either in combination with EBRT or as monotherapy, for early stage non-surgically managed endometrial cancer remains low with most patients receiving EBRT alone. Despite concerns of overtreatment in a population with competing causes of death, brachytherapy appears to result in improved survival.