There is accumulating evidence linking gastric infection with the spiral bacterium, Helicobacter pylori, to the cause of various gastric pathologies including gastritis, gastro-duodenal ulcerations and gastric cancers and lymphomas. 1±5 We demonstrated recently that gastric cancer is closely linked to H. pylori infection; approximately 92% of cancer patients were H. pyloriseropositive and 68% of them were H. pylori CagAseropositive. 6 Our study con®rmed recent retrospective studies presented by Danesh in his review on H. pylori infection and gastric cancer, showing that this infection SUMMARY Background: There is accumulating evidence for the role of Helicobacter pylori in the development of gastric cancer as well as of lymphomas that arise in mucosaassociated lymphoid tissue (MALT). We reported recently that gastric cancer patients show high prevalence of cagA-positive H. pylori and express gastrin and gastrin receptors enabling them to stimulate tumour growth in autocrine fashion. Aims: Since the H. pylori infection is considered to be more strongly associated with MALT lymphoma than with gastric cancer, we decided to determine the gastrin and its receptors' mRNA expression and gastrin content in this tumour as well as the release of this hormone both into plasma and gastric lumen. Twenty MALT lymphoma patients were compared with 100 age-and gendermatched controls with similar dyspeptic symptoms. Results: The overall H. pylori seropositivity in MALT lymphoma was about 90% and CagA positivity was 70%, compared to 56% and 33%, respectively, in controls. The serum gastrin in MALT lymphoma was