Currently, dissection of the axillary or regional lymph nodes is considered the standard staging procedure in breast cancer. However, accumulating evidence is becoming available that the sentinel node concept may provide the same or even better staging information. In the case of melanoma, it is proven that the histoiogical characteristics of the sentinel node reflect the histological characteristics of the distal part of the lymphatic basin. Morbidity can be reduced significantly by the use of sentinel node dissection as several authors have reported successful introduction of this technique into clinical practice. But in breast cancer patients, there are signigicant differences in practice relating to the technology, such as radiopharmaceuticals, injection sites, volume of injectate, combination with vital blue dye, preoperative lymphoscintigraphy, etc. Valuable reports on these topics appeared in recent journals. This review is a summary of those reports for nuclear physicians interested in sentinel node detection by lymphoscintigraphy in breast cancer patients.