Sentinel lymph node (SLN) biopsy is a standard procedure for axillary staging among patients with clinically node-negative breast cancer. Both the radioisotope and blue dye methods are well established for SLN identification. The indocyanine green (ICG) fluorescence method reveals subcutaneous lymphatic flow and enables the surgeon to navigate and perform sequential dissection of SLNs. The ICG fluorescence method has an equal or higher SLN identification rate compared to conventional methods, and there was no significant difference in the detection of positive SLNs between the ICG fluorescence and radioisotope methods. Hence, the ICG fluorescence method is an acceptable alternative to conventional methods for SLN detection. However, the accuracy of the ICG fluorescence method after preoperative systemic therapy has not yet been systematically evaluated; therefore, long-term follow-up data about survival and adverse events after the application of the ICG fluorescence method are needed to confirm the clinical significance of this method. The recent technological innovation in SLN mapping enables physicians to perform real-time navigation surgery for SLN biopsy. Here, we introduce the technical details and current data of SLN biopsy using the ICG fluorescence method, and describe the technical innovation of SLN mapping.