In a consecutive prospective series of 186 Swedish persons with the diagnosis of non-ulcer dyspepsia 71.5% were found to have gastritis and/or bulbar duodenitis in endoscopic biopsies. Gastroduodenitis was associated with campylobacter pylori (CP) in 83.5% of the cases. The double therapeutic approach using an antibiotic and a preparation containing bismuth in an uncontrolled therapeutic pilot trial resulted in improvement of the histological picture, disappearance of CP and amelioration of symptoms. It is concluded that CP-infection plays a central role in the pathogenesis of gastroduodenitis associated NUD.