The aim of the study is to determine the role of lymphadenectomy in advanced epithelial ovarian cancer. The data were obtained from the Surveillance, Epidemiology and End Results (SEER) program reported between 1988 and 2001. Kaplan -Meier estimates and Cox proportional hazards regression models were used for analysis. Of 13 918 women with stage III -IV epithelial ovarian cancer (median age: 64 years), 87.9% were Caucasian, 5.6% African Americans, and 4.4% Asians. A total of 4260 (30.6%) underwent lymph node dissections with a median number of six nodes reported. For all patients, a more extensive lymph node dissection (0, 1, 2 -5, 6 -10, 11 -20, and 420 nodes) was associated with an improved 5-year disease-specific survival of 26.1, 35.2, 42.6, 48.4, 47.5, and 47.8%, respectively (Po0.001). Of the stage IIIC patients with nodal metastases, the extent of nodal resection (1, 2 -5, 6 -10, 11 -20, and 420 nodes) was associated with improved survivals of 36.9, 45.0, 47.8, 48.7, and 51.1%, respectively (P ¼ 0.023). On multivariate analysis, the extent of lymph node dissection and number of positive nodes were significant independent prognosticators after adjusting for age, year at diagnosis, stage, and grade of disease. The extent of lymphadenectomy is associated with an improved disease-specific survival of women with advanced epithelial ovarian cancer.