Endoscopic submucosal dissection (ESD) is becoming the main procedure for the resection of early gastric cancer (EGC). The absolute indications for treating EGC with endoscopic resection were established by the Japanese Gastric Cancer Association and have been generally accepted. However, the absolute indications for treating EGC are rather strict, and expanded indications have been developed. Many studies have reported favorable long-term outcomes for patients who received curative resection for the expanded indication. ESD preserves the stomach, thereby improving patients’ quality of life compared to surgery; however, a generally higher incidence of metachronous gastric cancer has been reported after ESD for EGC. Therefore, clinicians must pay careful attention during surveillance endoscopy, even after a curative ESD. (Gut Liver 2018;12:119-124)