Gastric adenocarcinoma can be divided into two histopathological types: intestinal and diffuse. In addition to the role of environmental factors, an association between gastric cancer and Helicobacter pylori has been suggested. A retrospective study was therefore carried out among 46 patients who had gastric cancer. As a control group, 40 patients with non-malignant disorders were selected (11 patients with peptic ulcer, 12 with chronic superficial gastritis, 17 with chronic atrophic gastritis). Twenty-six cancers were classified as intestinal type and 20 as diffuse type. H. pylori was found in 23 (88 per cent) of the intestinal type and 11 (55 per cent) of the diffuse type (P < 0.05). Patients with the intestinal-type gastric cancer had a higher prevalence of H. pylori infection than those with gastric ulcer (55 per cent) and chronic superficial gastritis (50 per cent) (P < 0.05). These findings suggest that there is a possible association between the intestinal type of gastric cancer and H. pylori infection.