In order to investigate the relationship between Helicobacter pylori infection of the gastric mucosa and mucosal changes in portal hypertension, gastric fundic and antral biopsies were obtained from 66 patients with portal hypertension and 49 controls with non-ulcer dyspepsia (NUD). Gastric mucosa from portal hypertensive patients exhibited typical vascular dilatation and congestion, while mild dilatation of lamina propria blood vessels was not uncommon in NUD patients with histological evidence of gastritis. Colonization of the gastric mucosa by H. pylori infection was significantly less in portal hypertension (51.5%) compared to controls (75.5%; P < 0.01). The difference was more apparent in patients with marked vascular dilatation (18.8% colonization) compared to patients with minimal vascular dilatation (66.7%). H. pylori infection was significantly associated with active superficial gastritis (P < 0.001), and with atrophic gastritis (P < 0.001), in both study groups. H. pylori-negative superficial gastritis was significantly more common in portal hypertension (25/66 patients) than in controls (7/49; P < 0.05). H. pylori infection was not more common in patients who had undergone repeated sclerotherapy. The results suggest that the gastric mucosa of portal hypertension does not provide a hospitable environment for H. pylori colonization, particularly when mucosal congestion is marked. H. pylori infection does not add significantly to the gastropathy of portal hypertension.