BACKGROUND: Ten-day triple therapy is somewhat more effective than 7-day treatment for curing Helicobacter pylori infection. Recent studies have suggested that rabeprazole-a proton pump inhibitor with fast onset of acid inhibition-could raise the efficacy of 7-day therapies to the levels obtained with 10-day treatment. OBJECTIVE: To compare the efficacy of 7- and 10-day rabeprazole-based triple therapy for H. pylori eradication. PATIENTS AND METHODS: Four hundred and fifty-eight patients were randomized to 7 or 10 days of triple therapy, including rabeprazole 20 mg, clarithromycin 500 mg, and amoxicillin 1 g, all twice a day. Cure rates were evaluated by urea breath test. RESULTS: Two hundred and thirty-seven patients received 7-day and 221 received 10-day therapy. Groups were comparable in terms of demographic variables. Intention to treat cure rates were 73.8% (95% CI: 67-79%) for 7-day and 79.6% (95%: CI:74-85%) for 10-day therapy (p = 0.09). Per-protocol cure rates were 81.8% (95% CI:76-o86%) and 89.3% (95% CI: 84-93%), p = 0.02, respectively. Cure rates were similar in peptic ulcer patients but in subjects without ulcer they were clearly lower for 7-day therapy: 66% versus 77% by intention to treat (p = 0.08) and 73% versus 91% in the per-protocol analysis (p = 0.004). Side effects and compliance in the two groups were comparable. CONCLUSIONS: Seven- and 10-day triple therapies seem equally efficient in peptic ulcer patients. In contrast, 7-day therapy is significantly less effective in nonulcer dyspepsia patients. Ten-day therapy, therefore, seems preferable when treating nonulcer patients. © 2005 by Am. Coll. of Gastroenterology.