Biopsy of the first tumour-draining lymph node (sentinel node, SN) is bound to become the procedure of choice in regional staging of melanoma and breast cancer patients. Several radiopharmaceuticals have been developed for lymphoscintigraphy. In this paper we review the most frequently used radiopharmaceuticals for their appropriateness in the sentinel-node procedure. We conclude that accurate localization of SNs is demonstrated using technetium-99m-sulfur colloid (99mTc-SC), 99mTc antimony trisulfide colloid (99mTc-ATC) [10] and 99mTc nanocolloidal albumin (99mTc-CA). 99mTc-Ca and 99mTc-SC are both available in Europe. In the United States 99mTc-SC is the only registered tracer for lymphoscintigraphy.