Gastric epithelial turnover increase in Helicobacter pylori infection has been demonstrated by interventional and non interventional methods for proliferating cell detection. We have observed a progressive hyperproliferation with the progression of Helicobacter pylori-induced mucosal lesions until the development of intestinal metaplasia. A similar result has been reported in other studies in the succession from normal mucosa to gastric carcinoma even if interventional techniques show less conspicuous differences in comparison to non interventional ones, which give an overestimated picture of proliferation. Later studies show that Helicobacter pylori-related hyperproliferation reverses after eradication. We have observed that this reversibility does not occur in areas of intestinal metaplasia, where the oncoprotein ras p21, involved in early gastric carcinogenesis, is expressed. This finding agrees with that demonstrating that hyperproliferation in intestinal metaplasia or gastric cancer is not affected by Helicobacter pylori. Other oncogenetic changes in intestinal metaplasia (i.e., p53 mutation) may further explain the persistently modified proliferative pattern of the epithelium. Recent studies suggest a lack of reversibility of intestinal metaplasia after Helicobacter pylori eradication, but this problem remains controversial. Our experience suggests that the persistence of the bacterium may increase the extent of this lesion. In conclusion the development of intestinal metaplasia is associated with an impaired regulation of gastric epithelial proliferation. Nevertheless, from the biological point of view, the progression towards carcinoma requires further DNA changes. Moreover, many questions need to be answered in order to establish clear guidelines for the clinical management.