INTRODUCTION: intestinal metaplasia associated with Helicobacter pylori infection is a stage of the temporal sequence of histological lesions gradually induced by this microorganism. It is considered a preneoplastic lesion and its regression after eradication is controversial. AIM: to assess the evolution of intestinal metaplasia after eradication and to investigate whether metaplasia is a factor that contributes to successful treatment. MATERIAL AND METHODS: four hundred Helicobacter pylori positive patients were studied. Eradicating therapy was administered and endoscopic biopsies of gastric antrum and body were taken before and after eradication. Among other histological data, the presence of intestinal metaplasia was assessed. RESULTS: of all patients successfully treated, biopsies were taken before and after eradication in 268 of them: 71 (26,5%) had metaplasia before and 50 (18,7%) after eradication. A significant difference was observed in the outcome (p = 0,036) of the first eradicating treatment between the group without initial metaplasia (72,7%) and the group with initial metaplasia (61.2%). DISCUSSION: Helicobacter pylori eradication can revert intestinal metaplasia in some patients. On the other hand, the first treatment could be less successful in patients with intestinal metaplasia.