Gastroesophageal reflux disease (GERD) is responsible for a high proportion of digestive symptoms attributable to the upper gastrointestinal tract. Helicobacter pylori (H. pylori) is the main etiologic factor in chronic gastritis and gastroduodenal ulcer disease, but its relation with GERD has not yet been established. The aim of this paper is to review the relationship between H. pylori and GERD, trying to answer the question whether a nexus of "friendship" or "hate" exists between them. Although H. pylori may, in theory, represent a cause for GERD, available data suggest that the infection is not a risk factor for the development of GERD, and the microorganism could even represent a protective factor against this disease. The antisecretory effect of proton pump inhibitors (PPIs) seems to depend on the presence of the infection and H. pylori eradication has, therefore, negative consequences on the efficacy of antisecretory drugs (although its possible clinical relevance, precisely in patients with GERD, remains unknown). Moreover, H. pylori eradication in patients with duodenal ulcer disease is associated in some studies, but not in others, with a higher incidence of GERD, although the reported reflux esophagitis is usually mild. It can be concluded, from these data, that investigating or treating H. pylori infection is not recommended in patients with GERD (when these patients do not need PPI maintenance therapy). Finally, it has recently been recommended to eradicate H. pylori infection in those patients with GERD needing long-term treatment with omeprazole, as some studies have reported that this drug induces, in presence of the microorganism, an atrophic gastritis, with the consequent theoretic risk of gastric cancer. However, several arguments against this attitude can be postulated, and noteworthy are the following: many studies suffer important methodological defects, several authors report contrary results, and the possibility that H. pylori could play, as previously mentioned, a protective role against GERD. It may be concluded, therefore, that the indication of eradicating H. pylori in patients with GERD and maintenance therapy with PPIs, although supported by several arguments, cannot be considered as definitively established. In conclusion, H. pylori and GERD seem to have, in any case, a "friendly" relationship, although it may be transformed into one of "hate" when PPIs enter the scene.