Endoscopic mucosal resection (EMR), or mucosectomy technique, developed by Japanese endoscopists consists of resecting flat and polypoid neoplasms of the mucosa by longitudinal section through the submucosa. This technique is relatively simple and carries a low morbidity. It represents an important advance for endoscopists in both technical and cancer areas. Compared with the endoscopic methods of tumor destruction (laser, plasma coagulation), EMR presents the advantage of obtaining a complete specimen for histologic analysis.