Helicobacter pylori (Hp) infection is thought to play an important role in for the pathogenesis of atrophic gastritis and even gastric carcinoma. The ratio of Pepsinogen I/II (P I/II) also shows good correlation with atrophic gastritis and gastric ulcer. Since many hemodialysis (HD) and renal transplantation patients suffer from gastrointestinal problems, we investigated the importance of Hp infection and P I/II in these patients. Serum Hp IgG was measured by EIA. Pepsinogen titer was measured with antipepsinogen antibody-bearing beads and anti-pepsinogen antibody. Hp positive HD patients accounted for 50.7% of the subjects. Of the renal transplantation patients, 23.5% were positive with lower values than the HD patients. The value of P I/II in all patients with a high Hp positive titer also was low (under 3). In conclusion, serum IgG antibody to Hp and P I/II exhibit good correlation and both are useful for the diagnosis of atrophic gastritis in chronic renal failure.