OBJECTIVES This study was designed to assess the necessity of delayed complete axillary lymph node dissection (cALND) for patients whose sentinel lymph nodes (SLNs) were negative for tumors on intraoperative frozen section analysis, but later proven positive on hematoxylin and eosin staining or immunohistochemistry. METHODS We identified 341 patients who underwent sentinel lymph node biopsy (SLNB) with cALND at the Samsung Medical Center between 1998 and 2008, and reviewed the clinicopathological records of women diagnosed with invasive carcinoma of the breast. RESULTS Of the 341 patients, 59 underwent delayed cALND due to negative results on frozen section. Only 1 patient had a non-SLNs metastasis in the group of delayed cALND. Delayed cALND was associated with higher rates of breast-conserving surgery, smaller primary tumor and metastasis size in SLNs, fewer metastatic lymph nodes and SLNs and a lower TNM stage. The detection of metastases of SLNs on frozen section and the number of metastatic SLNs were related to the detection of additional metastases of nonsentinel lymph nodes (NSLNs) in cALND. CONCLUSION Our findings suggest that the lack of detection of metastases on frozen sections may be a predictive factor for nonmetastasis in NSLNs. cALND could therefore be omitted in such cases.