CC chemokine ligand 20 (CCL20) attracts CC chemokine receptor 6 (CCR6)-expressing cells. Using endoscopic biopsies taken from the gastric antrum of 42 subjects infected with H. pylori and 42 uninfected subjects, mucosal CCL20 mRNA and protein levels were measured by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. CCL19 mRNA and protein levels, as well as CCL21 mRNA levels, were also measured. The CCL20 mRNA and protein levels were significantly elevated in H. pylori-positive patients and substantially decreased after successful eradication. CCL19 and CCL21 expression levels were comparable in the H. pylori-infected and the uninfected groups. The CCL20 concentrations correlated with the degree of chronic gastritis. Immunohistochemistry and the in vitro infection assay showed that CCL20 was principally produced by the gastric epithelium. CCR6-expressing cells, including CD45RO(+) memory T lymphocytes and fascin(+)-CD1a(+) immature dendritic cells, infiltrated close to the CCL20-expressing epithelial cells. The CCL20/CCR6 interaction may be involved in the development of H. pylori-associated gastritis.