SUMMARYBackground: Low-dose rabeprazole-based triple therapy was effective for Helicobacter pylori eradication in a few Japanese studies. Aim: To compare the effectiveness of 1-week low-dose and high-dose rabeprazole-based triple therapy with those of omeprazole. Methods: One hundred and sixty-two H. pylori-infected dyspeptic patients were randomized to receive twice daily for 1 week either rabeprazole 10 mg (R 10 ), rabeprazole 20 mg (R 20 ) or omeprazole 20 mg (O) in combination with amoxicillin 1000 mg (A) and clarithromycin 500 mg (C). H. pylori status assessment was by the CLO test and histology at entry and by the