The status of the axillary lymph nodes is one of the most important prognostic factors in breast cancer. The presence or absence of metastatic lymph nodes is of primordial importance for the choice of adjuvant therapy. Early diagnosis of breast cancer, a result of widespread use of screening mammography, has increased considerably the number of detected in situ cancer and small invasive cancer without involved lymph nodes. Up to now there exists no conclusive study concerning the curative value of axillary dissection. In contrast, the complications of this procedure, especially in the long run, are non-negligible, creating controversy over its use. In situ carcinoma is no longer considered an indication for axillary dissection, nor is micro-invasive cancer (< or = 2 mm). In absence of accurate imaging and valid alternatives to exploratory surgery, new less traumatising procedures are currently under investigation: axillary fat aspiration with endoscopic axillary surgery, or the sentinel lymph node biopsy which is enlarged in case of a positive histology to a full axillary dissection. This approach will permit in the near future a reduction of morbidity to a strict minimum due to surgical treatment in the node-negative patient.