Sentinel node (SN) concept is valid in gastrointestinal (GI) malignancies. The dual tracer method with radio-guided and dye-guided SN mapping is feasible in GI malignancies and is useful in detecting unexpected aberrant drainage routes from GI cancers. SN mapping enabled us to perform individualized and step-wise lymphadenectomy in patients with GI cancer. A combination of SN mapping and endoscopic surgery will contribute to the improvement in quality of life after surgical treatment of GI cancer.