Endoscopic mucosal resection is a minimally invasive technique of resection of large pieces of the superficial layers (the mucosa and partially the submucosa) of the gut wall. In the present study we are presenting currently established indications, recent advances in the technique, early and long-term results of the treatment of esophageal, gastric and colorectal early cancer by endoscopic mucosal resection based on the review of the literature, educational materials and personal experience from the training of the first author (KZ) at the National Cancer Center in Tokyo, Japan. Endoscopic mucosal resection should be indicated for every superficial neoplastic lesion of the gut wall that can be safely removed in its entirety by experienced endoscopic team, and subsequently processed and evaluated properly by cooperating histopathologist specializing in gastrointestinal pathology. Eventually a detailed analysis of a resected specimen enables the precise assessment of curability of the procedure and establishment of the rational management of a patient. Curative endoscopic resection allows for regarding this procedure as sufficient and includes a patient into a follow-up program. Potentially curative endoscopic resection requires to consider the risk of lymph node involvement and discuss with a patient potential benefits and risk associated with surgical treatment or its withholding in reference to patients' age and health condition. Non-curative endoscopic resection requires to recommend an additional local (endoscopic resection, endoscopic ablation, brachytherapy) or surgical treatment after a detailed analysis with a patient a potential benefit and risk associated with each option. Despite enormous advance in medical knowledge the outcome of the gastrointestinal cancer treatment is still far unsatisfactory. Early diagnosis and treatment of less advanced cancer remains the most promising method of improvement of the outcome. We hope that popularization of the knowledge regarding early gastrointestinal cancer may improve their early detection rate and thereby the outcome of the treatment.