Background: A high Helicobacter pylori seroprevalence has been found in many extragastrointestinal disorders. Moreover, it has been reported that the risk of chronic bronchitis may be increased in H. pylori-infected patients. The aim of this study was to assess the H. pylori seroprevalence in patients with chronic bronchitis. Methods: We evaluated 144 patients with chronic bronchitis (81 men and 63 women, aged 53.2 ± 12.7 years) and 120 age and sex-matched control subjects. All enrolled subjects (bronchitic patients and controls) underwent an enzyme-linked immunosorbent assay (ELISA) IgG serologic test for H. pylori diagnosis. Results: A correlation between age and H. pylori IgG level was detected for both bronchitic patients (r = 0.42; P = 0.004) and controls (r = 0.44; P = 0.004). H. pylori seroposivity in the chronic bronchitis group was significantly higher than that in controls (83.3% vs 60%; P = 0.007). The mean serum concentration of IgG antibodies against H. pylori was also significantly higher in patients with chronic bronchitis than in the control subjects (38.7 ± 24.1 U/ml vs 25.9 ± 19.3 U/ml; P = 0.02). Conclusions: Helicobacter pylori infection may be associated with chronic bronchitis. Further studies should be undertaken to confirm our results and to clarify the potential underlying pathogenetic mechanisms. [ABSTRACT FROM AUTHOR]