Axillary node dissection in operable breast cancer provides an accurate way of staging the disease. With increased popularity of screening and earlier diagnosis, most women do not harbor axillary metastases, in which case, axillary lymph node dissection could be avoided. Sentinel node biopsy (SNB) gained rapid popularity because the technique could predict the presence of metastases in downstream lymph nodes, so that surgery and its associated morbidity could be safely avoided. SNB can be performed with injection of isosulphan blue subdermally and peritumorally alone or in combination with radio-guidance with technetium-99 labeled colloid injection. Radio-guided SNB is superior to the blue dye in identifying the SN, and a combined technique is still better. However, it failed to accomplish its objective in a proportion of cases where the sentinel node could not be identified even with expensive gadgetry like gamma probes. An overview of sentinel node studies showed that the node was found in only 85-90% of patients and the overall sensitivity in correctly predicting the negative axilla by sentinel node biopsy was only 94%. There was a false negative rate of 6.2% wherein the sentinel node was reported negative in presence of metastasis to non-sentinel nodes in axilla.