BACKGROUND In patients with squamous cell carcinoma of the vulva, lymph nodal, surgicopathologic variables have been studied rarely, although lymph node status is by far the most important prognostic factor. This study was designed to investigate surgicopathologic variables of lymph node metastases to evaluate their prognostic significance. METHODS In 75 patients with inguinal and/or pelvic lymph node metastases from squamous cell carcinoma of the vulva, the following parameters were studied: size and location of the tumor, depth of invasion, grade, lymph-vascular space involvement (LVSI), local immune reaction, presence and degree of dystrophic changes in the surrounding skin, FIGO stage, number of positive lymph nodes, greatest dimension of the metastasis within the lymph node, percentage of lymph node replacement, number of lymph nodes with replacement greater than 50%, number of lymph nodes replaced completely by tumor, extracapsular spread, and active immunologic response within the lymph node. RESULTS Among the variables related to the primary carcinomas, only size of the tumor and LVSI were correlated with survival (P < 0.003 and P < 0.02, respectively). On the contrary, all pathologic variables regarding the lymph nodes significantly influenced survival by univariate analysis. On multivariate analysis, extracapsular spread was the most significant independent prognostic factor (P < 0.0004), followed by FIGO stage (P < 0.03). For patients with only one positive lymph node, the most important prognostic factor was the greatest dimension of the metastasis within the lymph node (P < 0.01). CONCLUSIONS These data, if confirmed in larger series, can contribute to a more accurate identification of low and high risk patients and, therefore, to a more appropriate employment of adjuvant therapies.