Objectives: To treat previously untreated adult patients infected with Helicobacter pylori with one of two regimens in an ambulatory community setting to assess the efficacy and safety of these regimens, Methods: Sixty five adult patients with histologically confirmed H, pylori infection were randomly assigned in this open cohort study to 2 wk, low dose, twice daily treatment with omeprazole 20 mg and clarithromycin 250 mg (OC) (n = 31) or OC plus metronidazole 500 mg (OCM) (n = 34). At least 4 wk after treatment, H, pylori status was assessed by histology (four gastric biopsies, two each from antrum and body), Results: Triple therapy with OCM was significantly beater than dual therapy with OC in intent-to-treat (82.4 vs 58.1%, p = 0.03) and per protocol analysis (93.3 vs 62.1%,p = 0.004). Although there were frequent side effects (OC 19/31 61.3%; OCM 22/34 64.7% with at least one side effect), these were generally mild, and patients were able to complete nearly all of their medications (OC 97.2%, OCM 96.7% of pills taken), The only patient withdrawn due to medication side effects was in the OC arm, Conclusions: Triple therapy with OCM in a community setting eradicates H, pylori more effectively than dual therapy with OC, OCM is tolerated with high compliance despite frequent minor side effects and appears safe without the development of serious adverse events.