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Abstract Background and Objective: Helicobacterpylorus is the major cause ofinflammation andulcer instomach, and immunoglobulin IgG is one of the antibodies produced against it, which is important in the course and diagnosis of the previoussufferers. The awareness of the prevalence of this disease can be helpful for the physicians to choose the way of treatment. Material and Methods: In these cross-sectional study, 516patients referred to laboratory was studied. After separating the serum, Antibody Helicobacter pylori IgGtest wasdone by ELISA method. Results: of 516, 156 (30.2 %) of the patients have a positive result, 51(32.7%) are males and 105 (67.3 %) are females. Positive percent of males (43.5%) is greater than females (26.5%).Over-45-year-old women (9.8 %) have the highest percentage of disease titers. Conclusion: The percent of positive cases in men is more than that the women. Over-45-year-old women (9.8 %) have the highest percentage of positive case. Keywords: Helicobacter pylori IgG, Tehran, ELISA