BACKGROUND: We evaluated the feasibility and prognostic effect in axillary recurrence or survival of sentinel lymph node biopsy (SLNB) in patients with cytology-proven, node-positive breast cancer after neoadjuvant chemotherapy (NAC). METHODS: This is a retrospective study of 329 patients who were diagnosed with invasive breast cancer and axillary lymph nodes (ALN) metastasis and treated with NAC followed by curative surgery at Samsung Medical Center between January 2007 and December 2013. We analyzed and compared outcomes including prognoses and survival rates among all groups. RESULTS: The median age at the time of surgery was 44.4 years. The median follow-up time was 37 months (range, 1-91 months). The sentinel lymph node (SLN) identification rate was 96.7% (117 of 121 patients). The median number of retrieved SLNs was 4.0 (range, 1-7), and 57 patients had negative SLNs on frozen-section analysis. The false negative rate of SLNB after NAC was 7.8% (5 of 64 patients). In survival analysis, there was no difference in the overall survival (P = .2) and the regional recurrence-free survival (P = .297) among Groups 1, 2, and 4. CONCLUSION: SLNB may be feasible after NAC for node-positive breast cancer and may help reduce surgical morbidity by avoiding the need for standard axillary lymph node dissection in some patients. We suggest that future studies with a large number of patients and a longer follow-up period are necessary to support the use of SLN surgery as an alternative to axillary lymph node dissection in this patient population.