The final diagnosis of granulomatous gastritis is based on morphological findings and clinical and laboratory data. Detailed analysis of the morphological features of the granulomas together with associated mucosal changes could generate more information on aetiology and pathogenesis. Biopsies from 71 patients diagnosed as having granulomatous gastritis were reviewed. Thirty-seven of these patients (52%) had Crohn's disease. In 18 patients (25%) an isolated granulomatous gastritis was diagnosed. In seven patients (10%) the final diagnosis was a foreign body reaction. Of the remaining cases, four (7%) corresponded to tumour-associated granulomas and one case each of sarcoidosis (1%), Whipple's disease (1%) and vasculitis-associated disease (1%). Two cases (3%) were unclassifiable. The granulomas were mainly found in the antrum (64% antrum only, 11% antrum and corpus, 6% transitional mucosa corpus-antrum). Granulomas were usually small. This was particularly true for those found in patients with Crohn's disease. Multiple granulomas were observed in the sarcoidosis, the Whipple's disease and vasculitis-associated cases. A pattern of chronic gastritis with atrophy was present in 95% of the biopsies (68/71 patients). Helicobacter pylori was detected in 92% of the biopsies (64/71 patients).