Introduction. Infection by the bacterium Helicobacter pylori (H. pylori) is transmissible and is considered a public health issue which affects people of all ages. The objective of this study was to identify factors (lifestyles, dietary factors, and hygiene conditions) related to the prevalence of H. pylori infection. Methods. We carried out an observational cross-sectional study with a community sample of adults from the municipalities of Viseu and Sátão, Portugal. The final sample resulted in 166 adults. The data were collected through a self-Administered questionnaire with questions regarding sociodemographic aspects and lifestyles. H. pylori infection was identified using the 13C-urea breath test. Results. No association was found between the prevalence of H. pylori infection and the use of tobacco, alcohol, or coffee or dietary factors. The prevalence of H. pylori infection was higher in adults who reported higher consumption of fried food and lower consumption of vegetables and fruit. H. pylori infection was significant for the variables of lower frequency of handwashing before going to the bathroom (p=0.02) and well water consumption (p=0.05). Conclusion. A significant association was found for H. pylori infection with the lower frequency of handwashing before going to the bathroom and the consumption of well water.