Endoscopic mucosal resection (EMR) is a promising therapeutic option for removal of superficial carcinomas or premalignant lesions throughout the gastrointestinal tract. This review discusses indications and the several techniques of EMR in early tumors of esophagus, stomach, duodenum, and colon. EMR is not yet widely utilized in the West. However, great benefits may be obtained from this non-invasive technique after an accurate evaluation of patients and a careful staging of lesions that may assess the depth of infiltration and exclude the presence of lymph node metastases. EMR permits a complete removal of the lesion with histologic assessment of the entire specimen and the change in the pathologic stage in a significant number of patients. To minimize the risk of serious complications (mostly bleeding and perforation), only experienced endoscopists should undertake EMR in an appropriate environment. Data from literature are encouraging on the use of EMR, but a long-term follow-up of a large number of patients is necessary to confirm the effectiveness of this therapy.