Aims: To assess the therapeutic potential of clarithromycin, a new macrolide with high anti-Helicobacter pylori activity, given with bismuth salts and omeprazole in different regimens aimed at simplifying the treatment of H. pylori-related gastritis. Methods: Eighty-eight patients with proven H. pylori infection and gastritis were treated with one of the following four regimens: omeprazole 40 mg/day for one week (group A, n = 14); omeprazole 40 mg/day for one week followed by clarithromycin 1 g/day for 2 weeks (group B. n = 26); omeprazole 40 mg/day for one week followed by tripotassium dicitrato bismuthate 480 mg/day and clarithromycin 1 g/day, both for two weeks (group C, n = 26); and tripotassium dicitrato bismuthate 480 mg/day and clarithromycin 1 g/day for two weeks (group D, n = 22). Presence of H. pylori, histology and electron microscopy were assessed at entry and four weeks after the end of each treatment. Results: Omeprazole alone had no effect on H. pylori status. The highest eradication rate was obtained in group C patients (81%), a proportion significantly greater than that observed in group B (50%, P < 0.03) or group D patients (55%, P < 0.05). Conclusion: Sequential treatment may be a useful option in the treatment of H. pylori-related gastritis.