Sixty patients with Helicobacter Pylori positive non ulcer dyspepsia were randomly allocated to one of the following treatment groups: Group I--norfloxacin 400 mg bid for 10 days, Group II--amoxycillin 500 mg bid plus tinidazole 500 mg bid for 15 days, Group III--colloidal bismuth subcitrate (CBS) 240 mg bid for 4 weeks. H pylori elimination was achieved in 14%, 81%, and 62% in Groups I, II and III respectively. Eradication of H pylori was not observed in Groups I and II, but was achieved in 25% of patients in Group III. Antral gastritis improved in 69% in Group II and 50% in Group III. We conclude that norfloxacin is not effective in H pylori infection. A combination of amoxycillin and tinidazole is highly effective in H pylori elimination with improvement in associated gastritis, but H pylori eradication is not observed with this therapy. CBS is also effective in H pylori elimination though H pylori eradication is achieved in only 25%.