Objective To investigate the prevalence of Helicobacter pylori (Hp) infection in Chengdu and its risk factors. Methods Permanent residents in Chengdu who took routine health examinations in the West China Hospital of Sichuan University were recruited in the study. All participants received 14C-urea breath test (14C-UBT) for the diagnosis of Hp infection. A random sample (n=500) was drawn for a questionnaire survey. Results Of 8 365 participants, 53.1% were diagnosed with Hp infection. Higher prevalence was found in male participants (54.1%) than in female participants (51.7%,PPPP