Background: The axillary lymph node stage is one of the single most important determinants in the prognosis of breast cancer patients. The disadvantages of the two previous methods used for evaluating axillary node metastasis, i.e., axillary lymph node dissection and sentinel lymph node biopsy, have directed researchers to investigate new techniques for this purpose. The aim of the current study was to evaluate the clinical usefulness of axillary ultrasonography in detecting axillary metastasis.Methods: This study was conducted during a 12-month period. The breast cancer cases included in this study were all clinically diagnosed as stages I and II, with no prior treatment to the axillary region by surgery and/or chemo-radiotherapy. Excluded from the study group were patients with palpable axillary lymph nodes, those who had major organ failure or concomitant malignancy. All included patients with non-palpable axillary lymph nodes underwent axillary ultrasound examination. An ultrasound- guided core needle biopsy was performed on patients with suspected metastasis.Results: There were 125 female patients with a mean age of 49.6 years included in this study. From these, 16 (12.8%) cases had positive axillary sonographic findings. Pathologic evaluation of tissue specimens (taken by ultrasound-guided core needle biopsy) in 10 (62.5%) out of 16 patients were positive, and in the patient group of 6 (37.5%) cases, studies were negative. Axillary ultrasonography had a sensitivity of 35.7%, specificity of 93.8%, positive predictive value of 62.5%, and negative predictive value of 83.5%.Conclusion: The axillary ultrasonogram is a reliable technique in the determination of axillary nodal metastatic involvement in breast cancer patients. By use of this method a significant amount of complications and costs related to the previous techniques can be avoided.