Endoscopic submucosal dissection (ESD) is a safe and minimally invasive method for the treatment of early gastric cancer (EGC). However, whether ESD for EGC is also safe and feasible in patients aged ≥ 85 years is unclear. The patients enrolled in this study were divided into three groups: age ≥ 85 years (44 patients, 49 lesions), age 65–84 years (624 patients, 687 lesions), and age ≤ 64 years (162 patients, 174 lesions). We evaluated the incidence of adverse events (AEs) and overall survival (OS) and disease-specific survival (DSS). We analyzed the factors that had a significant impact on the prognosis of patients aged ≥ 85 years. No significant differences were found in the incidence of AEs among the three groups (p = 0.612). The OS was significantly lower in patients aged ≥ 85 years (p < 0.001). Conversely, DSS was not significantly worse in patients aged ≥ 85 years (p = 0.100). The poor Geriatric Nutritional Risk Index correlated with poor prognosis in patients aged ≥ 85 years (p < 0.001). ESD is a safe and valid treatment for EGC in patients aged ≥ 85 years. However, the indications should be carefully decided because it is difficult to estimate the survival contribution of ESD for EGC in patients aged ≥ 85 years, especially in those with poor nutritional status.