The diagnosis of axillary (AX) metastases remains a challenge in the management of breast cancer and is a subject of controversy. Clinical node staging clearly is limited in the assessment of AX lymph nodes. AX mammography, ultrasonography, and computed tomography (CT) do not provide histologic information. Although nuclear magnetic resonance imaging may have considerable value in the diagnosis of AX metastases, it does not detect micrometastases. The use of biologic markers in the assessment of AX metastases remains a subject of investigation. On the other hand, biopsy of selected AX nodes or tissue with examination of histology or cytology generally would not identify a significant percentage of patients with AX node involvement. Sentinel lymph node biopsy, however, might be potentially useful for assessing AX metastases, although it remains investigational. In order to simplify diagnosis and reduce morbidity and mortality, alternatives to AX dissection must be sought and imaging and staging modalities refined. We present a review of the literature pertaining to the diagnosis of AX metastases in patients with breast cancer and a discussion of some current areas of controversy.