Background and objective <p>Autoimmune gastritis (AIG) constitutes a distinct, immune-driven chronic gastritis marked by persistent and protracted mucosal inflammation, which can lead to gastric mucosal damage and potentially result in gastric neoplastic lesions. Pernicious anemia (PA) is considered the advanced stage of AIG. This study aims to summarize the incidence of gastric neoplastic lesions in AIG and PA patients.</p> Methods <p>Searches were finalized on 15 April 2025 within the following repositories: PubMed, Embase, and Web of Science. The incidence of gastric neoplastic lesions served as the primary outcome; subgroup tests and meta-regression traced heterogeneity origins.</p> Results <p>A total of 18 studies were included. In AIG patients, the incidence rates of gastric cancer (GC), low-grade dysplasia (LGD), and gastric neuroendocrine tumors (NETs) were 289.60, 657.44, and 1154.93 per 100,000 person-years, respectively. In PA patients, the corresponding incidence rates were 156.25, 1350.46, and 437.00 per 100,000 person-years. In PA studies, prospective design and the application of endoscopic histological examination improved GC detection rates. Meta-regression analysis showed that the incidence of GC in the PA population and NETs in the AIG population increased with more recent study enrollment periods, suggesting that advances in endoscopic diagnostic technology may have facilitated lesion detection. <i>Helicobacter pylori</i> (HP) status did not significantly affect these risks.</p> Conclusion <p>This study provides preliminary evidence of gastric neoplastic lesions in AIG patients. Rising GC incidence over time likely reflects improved endoscopic detection. These data inform clinical risk assessment and management strategies. Future research should standardize diagnostic criteria, account for comorbid autoimmune conditions, and reduce inter-study heterogeneity to better quantify risk in both AIG and PA populations.</p> Graphical abstract <p></p>