AIM: To investigate β-catenin expression in patients with intestinal metaplasia, and to look for a possible relationship between β-catenin expression and either epithelial proliferation values or Helicobacter pylori ( H pylori) infection.METHODS: Twenty patients with complete type intestinal metaplasia were studied. β-Catenin expression and epithelial cell proliferation in antral mucosa were assessed using an immunohistochemical analysis. Hpylori infectionwas detected by histology and a rapid urease test.RESULTS: Reduced β-catenin expression on the surface of metaplastic cells was detected in 13 (65%) out of 20 patients. Moreover, in eight (40%) patients intranuclear expression of β-catenin was found. When patients were analyzed according to Hpylori infection, the prevalence of both β-catenin reduction at the cell surface and its intranuclear localization did not significantly differ between infected and uninfected patients. Cell proliferation was higher in patients with intranudear β-catenin expression as compared to the remaining patients, although the difference failed to reach the statistical significance (36±8.9 vs 27.2±11.4, P = 0.06). On the contrary, a similar cell proliferation value was observed between patients with reduced expression of β-catenin on cell surface and those with a normal expression (28.1±11.8 vs26.1±8.8, P= 0.7).Hpyloriinfection significantly increased cell proliferation (33.3±10.2% vs 24.6±7.4%, respectively, P= 0.04).CONCLUSION: Both cell surface reduction and intranuclear accumulation of β-catenin were detected in intestinal metaplasia. The intranuclear localization of β-catenin increases cell proliferation. H pylori infection does not seem to play a direct role in β-catenin alterations, whilst it significantly increases cell proliferation.