Gastric cancer is still a major cause of mortality due to cancer worldwide. The most common type of gastric cancer is intestinal type carcinoma, which usually occurs in stomachs containing chronic atrophic gastritis. Individuals with chronic atrophic gastritis are considered to be at increased risk for developing intestinal type carcinoma of the stomach. To examine the association between chronic atrophic gastritis and other gastric cancer risk factors, a cross-sectional study was conducted using serum samples and questionnaire information collected from 776 persons of full Japanese ancestry in the greater Seattle area in 1994. The presence of chronic atrophic gastritis and Helicobacter pylori infection was determined by measurement of serum pepsinogen levels and H. pylori antibodies, respectively. Based on multiple logistic regression, the significant predictors of chronic atrophic gastritis were age over 50 years, H. pylori infection, and 20 years or more lived in Japan. Alcohol consumption, smoking, prior peptic ulcer, and history of gastric cancer in parents were not significantly associated with chronic atrophic gastritis. The results imply that H. pylori infection since earlier life and other unknown exposure factors in Japan might have played an important role in the development of chronic atrophic gastritis.