Aim of the work: Our study is designed to evaluate the prevalence of H. pylori infection by using anti H. pylori IgG antibodies in chronic renal failure patients (predialysis) and in chronic hemodialysis patients. Also try to find the effect of hemodialysis duration on anti H. pylori IgG titre.Subjects and Methods: This work was carried out in the Internal Medicine (Nephrology and Dialysis Unit) and the Clinical Pathology departments, Zagazig University Hospitals in the period from January 2006 to January 2007. This work included a total number of 80 subjects, were divided as Group I: Control group:Comprised 20 healthy volunteers (11 males and 9 females), with an age range from 20 to 62 years. They were not diabetic, hypertensive or smokers, Group II: chronic renal failure patients (predialysis) on conservative treatment: It comprised 20 patients with end stage renal disease on conservative treatment, Group III: (end stage renal failure on regular hemodialysis less than 5 years):It comprised 20 chronic renal failure patients on regular hemodialysis less than 5 years with hemodialysis duration from 6 to 52 month , Group(IV): (end stage renal failure on regular hemodialysis more than 5 years):It comprised 20 chronic renal failure patients on regular hemodialysis for more than 5 years with hemodialysis duration from 70 to 150 months.Results : our study showed that there was positive correlation between H. pylori titre and the age among control, predialysis and dialysis patients, also that the prevalence of H. pylori IgG was lower in predialysis and dialysis patients than in control group and the prevalence of H. pylori IgG titre decreased with the increased duration of dialysis, with significant difference among CRF patients (predialysis) , patients on dialysis less than 5 years and patients on dialysis more than 5 years. Also significant difference between patients on dialysis less than 5 years and patients on dialysis more than 5 years as regard to H. pylori IgG anyibody was detected.Conclusion :The prevalence of H. pylori IgG antibody titre was significantly lower in predialysis and dialysis patients than in control group. Also lower H. pylori IgG antibody titre was found in dialysis patients than predialysis patients, and the prevalence of H. pylori IgG titer decrease with the increased duration of dialysis.