To determine whether the "congestive" gastropathy associated with portal hypertension showed distinctive histological features independent of inflammatory gastritis, endoscopic biopsy specimens of gastric mucosa from 23 patients with portal hypertension and 25 patients with non-ulcer dyspepsia were examined. Active chronic gastritis associated with Campylobacter pylori was found in three patients with portal hypertension compared with 13 patients with non-ulcer dyspepsia. The changes of reflux gastritis were seen in nine patients with portal hypertension compared with three patients with non-ulcer dyspepsia. Mucosal capillary dilatation, assessed on sections stained for factor VIII related antigen, a specific marker for endothelial cells, was significantly greater in biopsy specimens from patients with portal hypertension but this difference was not apparent on sections stained conventionally. The degree of capillary dilatation was unrelated to the presence of histological gastritis. These observations support the view that portal hypertension is associated with a distinctive gastropathy characterised by prominence and dilatation of mucosal capillaries.