In this study we have performed a quantitative analysis of antral gastrin cells in 9 uraemic patients under dialytic treatment compared to a group of 10 chronic gastritis patients with a similar histological degree of gastritis. Immunocytochemistry was carried out on endoscopic biopsies of both groups. Using a computerised image analysing system we showed a significant increase of G-cell density (number of cells/mm2) in uraemic patients compared to non-uraemics (p < 0.001). These findings provide a further morphological basis for the elevation of gastrin levels in chronic uraemic patients, suggesting the existence of a specific factor inducing G-cell proliferation in these patients.