Backgrounds and Aims: The serological risk-prediction system combined the pepsinogen (PG) test, and anti-Helicobacter pylori antibody is available for evaluation of gastric cancer risk. In this system, chronic atrophic gastritis (CAG) or H. pylori infection is diagnosed. Subjects with H. pylori negative and PG test negative (group A) are supposed to be those who have never been infected with H. pylori and are at extremely low risk for gastric cancer. However, a certain proportion of patients with CAG has been identified as the extremely low-risk group (group A). Here we examined endoscopic atrophy and investigated its relationship with the ABC classification system. Methods: We examined 540 patients. All patients underwent an endoscopic examination for evaluating corpus atrophy. Fasting sera were collected and serum PGs and anti-H. pylori antibody (Hp-Ab) titer (E-plate Eiken) were evaluated. Results: Of the 540 patients, 306 were classified into group A. However, 136 of them showed signs of endoscopic atrophy (group A with CAG). Group A with CAG frequently comprised the elderly. A new titer cut-off (<3 U/mL) of the Hp-Ab improved the discrimination of group A with CAG by 8%. Conclusion: The prevalence of group A with CAG patients is a critical problem, especially in elderly subjects.