The purpose of this study was to examine the changes in gastric ghrelin and leptin with respect to Helicobacter pylori infection and whether such changes affect the plasma levels of leptin and ghrelin. In addition, we examined the relationship between changes in gastric mucosal ghrelin and leptin levels and gastrointestinal symptoms. Sixty-three patients diagnosed with chronic gastritis were enrolled in the study. Twenty-nine patients were Helicobacter pylori negative and 34 were Helicobacter pylori positive. Expression of ghrelin and leptin mRNA in the gastric mucosa was measured using endoscopic biopsies from the fundus. Plasma levels of ghrelin and leptin were measured by radioimmunoassay. Expression of leptin mRNA in the gastric mucosa was significantly higher in Helicobacter pylori-positive patients than in negative patients (0.38 +/- 0.17 vs. 0.24 +/- 0.12, p = 0.039). The expression of ghrelin was lower in positive patients than in the negative group, although this difference was not significant (p = 0.07). However, there was no significant difference in plasma leptin and ghrelin levels. Gastric mucosal ghrelin mRNA expression was significantly lower in patients with dyspepsia than in those without (0.15 +/- 0.11 vs. 0.23 +/- 0.20, p = 0.05). Helicobacter pylori infection and gastrointestinal symptoms could be associated with leptin and ghrelin expression in the gastric mucosa.