The international consensus conference from St. Gallen concerning the treatment of early breast cancer concluded in 2003, that sentinel node biopsy was now accepted as method allowing axillary staging in breast cancer. This procedure may avoid complete lymph node dissection in appropriate cases. Since numerous questions associated with the technique are still not defined and the procedure itself is not yet standardized, the German Society of Senology defined the conditions for the routine clinical use of sentinel node biopsy in an interdisciplinary consensus meeting.