Background Endoscopic resection (ER) of early gastric cancer (EGC) meeting the absolute indication has excellent long-term outcomes. Objective To compare long-term outcomes of ER with those of surgery in patients with EGC who met the absolute indication for ER. Design Retrospective cohort study. Setting A specialized center for the treatment of cancer. Patients and Interventions We retrospectively reviewed data from patients who underwent gastrectomy or ER for EGC between 2002 and 2007. Gastric cancers were differentiated-type adenocarcinoma without ulceration confined to the mucosal layer and 2 cm or smaller in size. Main Outcome Measurements The primary outcome was overall survival (OS). Metachronous cancer rates and adverse event rates were compared. Kaplan-Meier plots and Cox proportional hazard regression analyses were applied for comparisons. Differences in baseline characteristics were adjusted by propensity score. Results Among 375 patients, 261 underwent ER and 114 underwent surgery. The median follow-up duration was 76.4 months. The 5-year OS rates did not significantly differ between the ER and surgery groups (95.7% vs 93.6%, respectively; P  = .725 by log-rank test). There were no gastric cancer–related deaths in either group. Metachronous gastric cancer developed more frequently in the ER group (6.1%, 16/261) than in the surgery group (0.9%, 1/114) ( P  = .024). However, most patients (93.8%, 15/16) in the ER group were curatively treated with repeat ER. Adverse event rates were higher in the surgery group than those in the ER group (7.9% vs 2.7%, P  = .028). Limitations Retrospective, single-center study. Conclusions The OS rate after ER for mucosal gastric cancer that met the absolute indication was comparable to that achieved with surgery. Although metachronous cancers were more common after ER, they were usually treatable and did not affect survival.