Dissection of the sentinel lymph node has become a standard procedure in the management of early-stage breast cancer and melanomas. A learning-curve is required, together with the proper validation of the technique by surgeons, nuclear medicine specialists, and pathologists before abandoning the orthodox lymph node dissection. The aim of this technique is the rationalization of the axillary lymph node dissection and thus diminishing morbidity. Several vital stains, such as patent blue, isulphan blue, and, among us, methylene blue, are utilized for the detection of the sentinel node. Also, the radiolocalization techniques of nuclear medicine by means of the injection of colloidal sulphur labelled with 99Tc and the intraoperative use of a gamma probe. All techniques should yield a detection rate superior to 90%, with a false-negative rate below 5%. We hereby report a literature review together with our experience at the Breast Clinic of Clinica del Country, Bogota, Colombia, where 82% of our cases present with breast cancer in the early stages. Our report is based on the experience with 277 cases collected between January 1998 and January 2005. Our annual rate of detection of the sentinel lymph node is above 98%, with a false negative rate of 7%. We have avoided the axillary dissection in 87% of our patients with early-stage invasive breast carcinoma. This novel technique has become the standard procedure in the management of early stage breast carcinoma and a clinically negative axilla.