Eradication of Helicobacter pylori is accompanied by an array of metabolic and hormonal changes in the host. Weight gain following H. pylori eradication is a poorly understood phenomenon and probably results from an interaction between multiple factors. Ghrelin, a peptide hormone secreted by the stomach, is involved in the regulation of food intake and appetite and may account for some of these changes. Although several observational studies have demonstrated that H. pylori infection suppresses circulating ghrelin levels, it has yet to be proven that ghrelin levels increase following eradication. On the other hand, gastric expression of ghrelin, also suppressed by H. pylori, clearly increases following eradication. The determinants of plasma ghrelin levels remain elusive, as do the effects of eradication on these levels. Weight gain following H. pylori eradication may be attributable to changes in plasma and gastric ghrelin; however, this hypothesis needs to be further investigated.