Objective To compare the histopathological features and treatment efficacy of different methods for metachronous early gastric cancer (MEGC) in the remnant stomach. Methods A total of 66 patients [38 endoscopic submucosal dissection (ESD) and 28 gastrectomy] with MEGC in the remnant stomach from January 2014 to December 2020 in Drum Tower Hospital were divided into the ESD group and the gastrectomy group. The baseline characteristics, histopathological features, treatment efficacy, and cost differences of the two groups were analyzed. Results The MEGC in the remnant stomach mostly occurred in elderly male patients, with the mean age of 69.7±8.5 years. The mean interval of the occurrence of MEGC in the remnant stomach was 6 years. As for the tumor location, the gastric body (31.6%) was the main location in the ESD group and gastric cardia (53.6%) in the gastrectomy group with significant difference (χ2=11.07, P=0.026). The mean operation time, hospital stay, postoperative fasting time, and total treatment cost were 80.0 min, 6.0 d, 1.5 d, ¥19 436 in the ESD group and 215.0 min, 19.0 d, 6.5 d, and ¥68 665 in the gastrectomy group, respectively, with significant differences between the two groups (P<0.05). The overall survival rate during follow-up was 76.3% in the ESD group and 71.4% in the gastrectomy group with no significant difference between the two groups (χ2=0.736, P=0.778). In terms of postoperative complications, the incidences of bleeding and infection were 7.9% and 5.3% in the ESD group, and those of obstruction and infection were both 14.3% in the gastrectomy group. There was significant difference in the incidences of postoperative obstruction between the two groups (P<0.05). Conclusion ESD is safe and effective for MEGC in the remnant stomach and is better than gastrectomy in terms of the treatment cost and operation time, but the long-term efficacy still needs to be validated by large-scale prospective studies.