Purpose: Axillary lymph node dissection (ALND) is the gold standard of care for breast cancer patients showing metastases with positive sentinel nodes.In order to avoid unnecessary sentinel node biopsy (SNB), accurate evaluation of the axillary node is important.Axillary ultrasound (AUS), positron emission computed tomography (PET-CT), and magnetic resonance imaging (MRI) are useful for preoperative studies.If these imaging modalities reveal metastasis in the axillary nodes, patients should undergo axillary fine-needle aspiration (FNA).In this study, we evaluated the impact of preoperative axillary imaging and axillary FNA to determine the correct application of SNB.Patients and Methods: A retrospective chart review was performed on 209 patients, who underwent surgery for breast cancer between August 2008 and November 2010.We assessed the ability of axillary imaging to predict metastases in the axillary nodes and examined whether it was possible to avoid unnecessary SNB using axillary FNA.Results: The sensitivity and specificity ofAUS, PET-CT, and MRI were 56.9%, 91.7%; 59.6%, 96.9%; and 43.6%, 93.7%, respectively.All patients found to have malignancy using axillary FNA were also found to have axillary-node involvement.Thirty-three of 49 patients with suspected metastasis on AUS underwent axillary FNA.Twenty-six (78.8%) of them had metastasis in the axilla.Nine of 16 patients who refused axillary FNA had metastasis in the axilla.Only 28 of 160 patients (17.5%) who did not have axillary metastases on AUS had metastases in the axilla.Fifteen of 28 patients were found to have suspected metastases in axilla as per PET-CT or MRI.Conclusion: It is important that SNB is performed in patients selected using axillary FNA with preoperative imaging.