OBJECTIVE To determine if the extent of lymphadenectomy as determined by lymph node count from an inguinal-femoral lymph node dissection for vulvar cancer impacts overall survival (OS) and disease-specific survival (DSS) in patients with node-negative disease. METHODS Patients with stage I, II and III squamous cell carcinoma of the vulva who underwent primary inguinal-femoral nodal dissection were identified from the Surveillance, Epidemiology and End Results Program between 1988 and 2003. Patients were divided into 2 groups, those with <or=10 nodes and those with >10 nodes removed, and analyzed according to stage. All patients with histologically positive nodes were excluded. Log-rank test was done for univariate analysis. Cox regression method was used for multivariate analysis. RESULTS Squamous cell vulvar cancer was identified in 1030 patients. Statistically significant differences were seen on univariate analysis of OS between stage II and III patients with <or=10 and >10 nodes removed. The difference in 5-year DSS survival was statistically significant only for patients with stage III disease. On multivariate analysis age, stage and number of lymph nodes removed were all found to be significant variables affecting OS and DSS. CONCLUSIONS The removal of greater than 10 lymph nodes was associated with a significant improvement in DSS in patients with stage III vulvar carcinoma. This improvement in survival may be due to removal of micrometastatic disease in the inguinal lymph nodes. These data suggest that a thorough inguinal-femoral lymph node dissection should be performed in patients with advanced-stage node-negative vulvar carcinoma.