5009 Background: To evaluate the role of surgical staging of patients with grade 1 endometrioid uterine cancer. Methods: Data including stage, histology, grade, lymph nodes involvement and disease-specific survival were extracted from Surveillance, Epidemiology, and End Results Program from 1988 to 2001. Kaplan-Meier and Cox proportional hazards analyses were used to determine the predictors for survival. Results: 12,712 women were diagnosed with endometrioid carcinoma which included 3,867 (30.4%) with grade 1, 5,285 (41.6%) with grade 2, and 3,560 (28%) with grade 3 disease. The 5-year disease specific survival of patients with grade 1, 2, and 3 disease was 97.78% ± 0.29, 92.14% ± 0.45, and 78.04% ± 0.82, respectively. Of all the patients with nodal involvement, 10% had grade 1, 39% had grade 2 and 51% had grade 3 disease (p < 0.001). Positive nodes were found in 3% of grade 1, 9% of grade 2 and 18% in grade 3 tumors (p < 0.001). Of the 3,867 patients with grade 1 disease, 3,281 (84.9%) had stage I, 317 (8.2%) had stage II, 166 (4.3%) had stage III, and 103 (2.7%) had stage IV disease. Fifteen percent of the patients with grade 1 disease had extra-uterine spread, including 8% to the cervix, 4% to the pelvis and 3% to the upper abdomen or distant metastases. Conclusions: Grade 1 uterine cancers have a risk of extra-uterine spread. Given that the information obtained from a thorough staging procedure clearly influences adjuvant treatment decisions, complete surgical staging is recommended. No significant financial relationships to disclose.