The axillary nodal status is accepted universally as the most powerful prognostic tool available for early stage breast cancer. The removal of level I and level II lymph nodes at axillary node dissection (ALND) is the most accurate method to assess nodal status, and it is the universal standard; however, it is associated with several adverse long-term sequelae. Lymphatic mapping with sentinel lymph node biopsy has emerged as an effective and safe alternative to the ALND for detecting axillary metastases. This article discusses some lymphatic mapping methodology.