Background: The endoscopic surgery for the breast diseases has been proven safe and aesthetic and named as video-assisted breast surgery (VABS). We also applied it for sentinel node (SN) biopsy. We firstly succeeded to fuse the single photon emission computed tomography (SPECT) with 3D-CT mammary lymphography (LG). It can show the detailed position of all SNs with or without RI uptake. Method: In 3D-CT LG, 2 ml of Iopamidol 300 was injected subcutaneously above the tumor and the periareola. CT scan was taken 1 minute after injection to produce a 3D image of lymph ducts and nodes. In the lymphoscintigraphy, 99mTc phytate 74mBq was injected, and SPECT was taken after 2 hours. We fused it with 3D-CT LG. SN biopsy was performed endoscopically by dye and RI method. The endoscopic view showed stained lymph ducts and SNs, which can be navigated by RI detector gamma probe. Results: We have performed SN biopsy with 3D-CT LG on 160 patients, RI with 3D-CT LG on 32 patients, and SPECT fused 3D-CT LG on 20 patients. We could detect the position of RI-positive SN on the axillary lymphatic mapping of SPECT-fused 3D-CT LG by a gamma probe during surgery. The average sampled number of SN was 2.3. The dye-negative SN and RI-negative SN could be removed endoscopically. There was no false negative study. The wound scars were only 1 cm long, and were inconspicuous and aesthetic. Conclusions: The endoscopic SN biopsy is aesthetic and less invasive, which is facilitated by SPECT-fused 3D-CT LG.