Objective To explore if the addition of adjuvant chemotherapy with paclitaxel and carboplatin to radiotherapy confers an advantage for overall survival (OAS), and progression free survival (PFS); to assess the incidence of relapses over standard pelvic radiotherapy; and to evaluate the related toxicity in high-risk stage I-II endometrial carcinoma Methods Medical records were reviewed to identify high-risk stage I-II endometrial carcinoma cases treated in the Clinical Oncology and Nuclear Medicine department between 2002 and 2008 with adjuvant radiotherapy alone (arm I) (57 patients) or with sequential carboplatin (AUC5-6) and paclitaxel (135?175 mg/m2) with radiotherapy (arm II) (51 patients). Radiotherapy was performed through the four-field box technique at doses of 45?50 Gy (1.8 Gy/day × 5 days/week).Results The toxicity was manageable and predominantly hematologic with a grade 3 neutropenia and thrombocytopenia in 9.8% and 6% of the patients in arm I and arm II, respectively, without febrile neutropenia. All patients experienced hair loss. Chemoradiotherapy arm was associated with a lower incidence rate of relapse (9.8% vs. 22.7%). After a median follow-up period of 48 months, the 5-year OAS and PFS rates for chemoradiotherapy-treated patients were significantly more favorable than those who did not receive chemotherapy (P=0.02 and 0.03, respectively). In arm I, the OAS and PFS rates were 73.7% and 66.7% compared with those in arm II, whose rates were 90.2% and 84.3%. Conclusions Adjuvant chemoradiation with paclitaxel and carboplatin improved the survival rates and decreased the recurrence rates in patients with high-risk stage I-II endometrial carcinoma. Chemotherapy was associated with an acceptable rate of toxicity.However, a prospective study with a larger number of patients is needed to define a standard adjuvant treatment for high-risk stage I-II endometrial carcinoma.