We attempted to clarify the pathogenesis of gastric inflammation in the cardia. Eighty Japanese participated in this study. Biopsy specimens of the gastric antrum, corpus, and cardia (1 cm from the squamocolumnar junction) were obtained, and histological gastritis was evaluated. Cardiac inflammation was also evaluated using magnifying gastroscopy. We examined Helicobacter pylori infection, gastric juice pH/bile acid (BA), serum pepsinogen and gastrin levels, gastroesophageal reflux disease (GERD), and habitual smoking and assessed the relations between these factors and cardiac inflammation. The prevalence of H. pylori infection was statistically higher in patients with cardiac inflammation than in those without inflammation (P < 0.05). The relationship was also demonstrated by magnifying gastroscopy. Cardiac inflammation was linked to low acid output but not linked to the BA concentration or habitual smoking. Cardiac inflammation was more pronounced in patients without GERD. These results suggest that H. pylori is a major risk factor for cardiac inflammation in the Japanese.