Background: To determine if the sequencing of chemotherapy with external beam radiotherapy (EBRT) in the adjuvant setting for FIGO stage III endometrial cancer impacts 2-year progression free survival (PFS). Methods: As part of our Gynecologic Oncology Multidisciplinary Group's initiative to establish an institutional guideline for the adjuvant treatment of Stage III endometrial cancer, we reviewed 144 cases identified by our cancer registry and departmental database. Treatment regimens were divided into three categories: sequential therapy with six cycles of carboplatin/taxane followed by EBRT, concurrent cisplatin for two cycles with EBRT followed by four cycles of carboplatin/taxane, or ‘sandwich’ therapy with three cycles of carboplatin/taxane followed by EBRT followed by three cycles of carboplatin/taxane. The published results of the phase III GOG-258 study called into question the efficacy of concurrent chemoradiation. Therefore, we only compared sequential versus ‘sandwich’ therapy using a Chi-Square analysis. We conducted a retrospective chart review to assess if patients were able to complete the prescribed six cycles and EBRT, and then measured their PFS at two years. We hypothesized that there would be no difference in PFS between the two groups. Results: There were no significant differences in clinical or pathologic factors between patients treated with either regimen. Ninety-four patients (65%) had stage IIIC disease. The majority of patients received six cycles of paclitaxel with carboplatin. Median EBRT dose was 45 Gy. There was no statistically significant difference in the estimated 2-year PFS between the sequential and ‘sandwich’ groups, which were 82% and 82.5%, respectively (p = 0.84). Conclusions: Adjuvant chemoradiation for FIGO stage III endometrial cancer given sequentially or in a ‘sandwich’ fashion appears to offer equally excellent early clinical patient outcomes.