The aim of this study was to assess whether clinical work constitutes a risk factor for Helicobacter pylori infection among employees in hospitals. The prevalence of H. pylori infection was analysed in 249 individuals employed in a university teaching hospital according to three categories of hospital workers: (A) personnel from gastrointestinal endoscopy units (N=92); (B) personnel from other hospital units with direct patient contact (N=105); and (C) staff from laboratories and other units with no direct patient contact (N=52). Stool samples from each subject were examined with a validated enzyme-linked immunosorbent assay for the presence of H. pylori antigens. A questionnaire inquiring about sociodemographic and occupational characteristics was completed by each participant. The prevalence of H. pylori infection was 37.0% in group A, 35.2% in group B and 19.2% in group C (P<0.05). Among the different healthcare categories, nurses had a significant higher prevalence of H. pylori infection (P<0.01). No significant association was found between the length of employment or exposure to oral and faecal secretions, and H. pylori infection. Hospital work involving direct patient contact seems to constitute a major risk factor for H. pylori infection compared with hospital work not involving direct patient contact.