The classical treatment of neoplastic lesions is surgical resection. Improved detection of early lesions has offered new therapeutic strategies. Thus, for the last 20 years it has been increasingly attempted to undertake endoscopic resection of such tumors. While there is no doubt that morbidity and mortality are lower than after surgery, it was assumed that the long-term prognosis is not as good as with surgery. Surprisingly, however, the 5-year survival rates are excellent. Therefore, in local mucosal lesions of colon, stomach, and esophagus, endoscopic removal has become standard treatment. In Barrett's esophagus, the treatment modality it is still discussed controversially, despite encouraging results. Since we are yet not able to completely eliminate the premalignant specialized intestinal epithelium of the esophagus, it is still uncertain whether eradication of the malignant or dysplastic lesion is sufficient.