We compared the prognostic value of surgical lymph node staging after preoperative chemotherapy relative to other patient and tumor variables in 136 patients with locally advanced breast cancer (T3-4 and/or N2-3) who received preoperative chemotherapy followed by mastectomy and axillary dissection as part of a prospective protocol. Univariate analysis revealed that the number of metastatic lymph nodes, clinical tumor stage at presentation, clinical and pathologic response, and menopause status were significant variables associated with survival and disease-free survival, but clinical node stage at presentation and estrogen receptor status were not. The number of metastatic lymph nodes had more prognostic value than the other factors, and when evaluated by multivariate regression, surgical node staging added significantly more information to the remaining variables. Surgical staging is an important component of treatment for patients with breast cancer undergoing preoperative chemotherapy because it can provide an accurate and quantitative method for subgrouping patients with different survival rates and it can be used to compare results between preoperative chemotherapy trials.