Background/Aims: H. pylori infection and gastric metaplasia are frequently associated in patients with duodenal ulcers. However, the pathogenesis of duwlenal ulcer in relation to H, pilori infecrif' intlammation anci H. pylori. Conclusions: These results suggest that gaslric metaplasia in the duodenum and concurrent H. pilori infection may play a synergistic role in the pathogene.I. Vt' duodenal ulcer. (Korean J Gastroenterol 199S;27: 617-62S)