AIM: To assess H pylori seroprevalence in lung cancer and determine whether there is a potential association between lung cancer and H pylori infection. METHODS: The study was conducted on forty consecutive patients with lung cancer, confirmed by pathology (32 men, 8 women; mean age 55.50 ± 11.91 years, range 16-77 years). Forty healthy subjects (25 men, 15 women; mean age 43.08 ± 12.60 years, range 20-79 years) from the patients’ family members were matched to each case subject on the basis of age and socioeconomic status. H pylori infection was detected with a commercially available immunoglobulin G (IgG) enzyme-linked immunosorbent assay (Trinity kit, Biotech co., USA), previously validated in adults (86% sensitivity, 96% specificity) against a gold standard of culture and histology. RESULTS: H pylori seropositivity was present in 52.5% of patients with lung cancer in comparison to 45.0% of healthy control subjects. Although H pylori seropositivity was more frequent in lung cancer patients than in controls, the difference did not reach statistical significance (OR = 1.35, 95% CI = 0.56-3.25; P = 0.65). In addition, there was no significant difference between cases and controls in terms of gastrointestinal symptoms. CONCLUSION: The earlier described association between H pylori infection and lung cancer was not supported in this study. Further studies with larger sample sizes should be undertaken to assess the frequency of H pylori infection in patients with lung cancer and their potential association. AIM: To assess H pylori seroprevalence in lung cancer and determine whether there is a potential association between lung cancer and H pylori infection. METHODS: The study was conducted on forty consecutive patients with lung cancer, confirmed by pathology (32 men, 8 women; mean age 55.50 ± 11.91 years, range 16-77 years). Forty healthy subjects (25 men, 15 women; mean age 43.08 ± 12.60 years, range 20-79 years) from the patients’ family members were matched to each case subject on the basis of age and socioeconomic status. H pylori infection was detected with a commercially available immunoglobulin G (IgG) enzyme-linked immunosorbent assay (Trinity kit, Biotech Co., USA), previously validated in adults (86% sensitivity, 96% specificity ) against a gold standard of culture and histology. RESULTS: H pylori seropositivity was present in 52.5% of patients with lung cancer in comparison to 45.0% of healthy control subjects. Although H pylori seropositivity was more frequent in lung canc er patients than in controls, the difference did not reach statistical significance (OR = 1.35, 95% CI = 0.56-3.25; P = 0.65). In addition, there was no significant difference between cases and controls in terms of gastrointestinal symptoms. CONCLUSION : The earlier described association between H pylori infection and lung cancer was not supported in this study. Further studies with lung cancer was not supported in this study. Further studies with lung cancer was not supported in this study. Further studies with lung cancer was not supported in this study.