Endoscopic submucosal dissection (ESD) in patients with early gastric cancers (EGCs) in the remnant stomach is technically difficult, owing to the limited space and fibrosis under the suture lines and anastomoses. Conversely, ESD for patients with EGCs in the remnant stomach is less invasive and provides better quality of life than completion total gastrectomy. To clarify the effectiveness and safety of ESD, we reviewed the medical records of patients with EGCs in the remnant stomach who underwent ESD between July 2006 and October 2020 at our institution. All identified patients were included in the analysis. Of 25 patients with 27 lesions, the en bloc and R0 resection rates were 88.9% and 85.2%, respectively. Neither perforation nor postoperative bleeding was observed. During a median follow-up period of 48 (range, 5–162) months, the 5-year overall survival rate was 71.0%, whereas the 5-year cause-specific survival rate was 100%. No obvious differences in the outcomes of procedures with suture line involvement and without suture line or anastomosis involvement were noted. In conclusion, ESD was effective and safe in patients with EGCs in the remnant stomach despite the suture line involvement.