Non-ulcer dyspepsia (NUD) is a poorly understood syndrome often present in association with gastritis. Among patients undergoing gastroscopy, some with NUD have a gastric mucosa colonized by the campylobacter-like organism, Campylobacter pylori. We therefore studied prospectively 55 consecutive patients with NUD and 15 normal controls to determine the prevalence of C. pylori organisms, and to investigate their association with histological gastritis, macroscopic evidence of gastritis, sex, smoking, alcohol consumption, and dyspeptic symptoms. We found a 45.4% prevalence in NUD patients which was statistically significantly higher than the 13.33% prevalence in the control group (p less than 0.05). We also found a close association between C. pylori and microscopic evidence of gastritis (p less than 0.001), male sex (p less than 0.001), and postprandial bloating (p less than 0.05). We did not find any significant association between C. pylori and macroscopic evidence of gastritis, smoking, alcohol consumption and other dyspeptic symptoms. Our findings suggest that C. pylori may play a pathogenic role in NUD.