It is not uncommon that first lymph node involvement appears at a distant lymph node not at a nearest node from the primary lesion in patients with esophageal cancer. Identification of the sentinel node, which permits the detection of the first draining node from a primary lesion, is expected to individualize the treatment of esophageal cancer. From our study in 23 patients with esophageal cancer using Tc-99 m tin colloids, the sentinel node concept seemed to be applicable to patients with esophageal cancer (-pT2). However, injection techniques and intraoperative probe searching for hot nodes are more difficult and uncertain in esophageal cancer compared to superficial cancers such as breast cancer and malignant melanoma. Further studies are necessary to reliably apply the sentinel node biopsy technique to patients with esophageal cancer.