Background There are various methods for detecting sentinel lymph nodes in breast cancer. Sentinel lymph node biopsy (SLNB) using a vital dye is a convenient and safe, intraoperatively preparative method to assess lymph node status. However, the disadvantage of the dye method is that the success rate of sentinel lymph node detection depend on the surgeon's skills and preoperative mapping of the sentinel lymph node is not feasible. Currently, a vital dye, radioisotope, or a combination of both is used to detect sentinel nodes. Many surgeons have reported successful results using either method. In this study we have analyzed breast lymphatic drainage pathways using indocyanine green (ICG) fluorescence imaging. Methods We examined the lymphatic courses, or lymphatic vessels, in the breast using ICG fluorescence imaging, and applied this method to SLNB in patients who underwent their first operative treatment for breast cancer between May 2006 and April 2008. Fluorescence images were obtained using a charge coupled device camera with a cut filter used as a detector, and light emitting diodes at 760 nm as a light source. When ICG was injected into the subareola and periareola, subcutaneous lymphatic vessels from the areola to the axilla became visible by fluorescence within a few minutes. The sentinel lymph node was then dissected with the help of fluorescence imaging navigation. Results The detection rate of sentinel nodes was 100%. 0 to 4 states of lymphatic drainage pathways from the areola were observed. The number of sentinel nodes was 3.41 on average. Conclusions This method using indocyanine green (ICG) fluorescence imaging may possibly improve the detection rate of sentinel lymph nodes with high sensitivity and compensates for the deficiencies of other methods. The ICG fluorescence imaging technique enables observation of breast lymph vessels running in multiple directions and easily and accurately identification of sentinel lymph nodes. Thus, this technique can be considered useful.