Sentinel node biopsy for breast cancer patients has recently been applied as a less invasive, highly accurate alternative to axillary lymph node dissection. Numerous studies have shown that sentinel nodes accurately diagnose axillary staging. However, many problems remain to be answered and must be addressed before sentinel node biopsy becomes the standard surgical procedure for patients with breast cancer. We reviewed and discussed here three of these problems; axillary sampling as an alternative to sentinel node biopsy, dye method vs. combination of dye and radiocolloid for sentinel node biopsy, and intraoperative sentinel node examination. Further investigation will continue to be necessary as we learn how to better provide procedure of sentinel node biopsy.