Recent reports described some cases of gastritis in man caused by an uncultured gram-negative spiral bacterium morphologically identical to organisms observed in the stomachs of mammalians (e.g. cats, dogs, pigs). The aim of the present study is to confirm the presence of these bacteria in Italian swine. Tightly spiralled organisms (Gastrospirillum suis) were found in the stomach of eight (9.4%) out of 85 pigs examined. The bacteria were always associated with macroscopic lesions indicative of gastritis. Attempts to culture H. pylori or Helicobacter-like organisms were unsuccessful. The possibility that Gastrospirillum may be a zoonotic pathogen, with transmission occurring from pigs to humans, is discussed.