BACKGROUND: Peptic ulcer disease is the cause of dyspepsia in about 10% of people. Ninety-five percent of duodenal and 70% of gastric ulcers are associated with Helicobacter pylori. Eradication of H. pylori reduces the relapse rate of ulcers but the magnitude of this effect is uncertain. This is an update of Ford AC, Delaney B, Forman D, Moayyedi P. Eradication therapy for peptic ulcer disease in Helicobacter pylori-positive patients. Cochrane Database of Systematic Reviews 2006, Issue 2. Art. No.: CD003840. DOI: 10.1002/14651858.CD003840.pub4. OBJECTIVES: To assess the proportion of peptic ulcers healed and the proportion of participants who remained free from relapse with eradication therapy against placebo or other pharmacological therapies in H. pylori-positive people.To assess the proportion of participants that achieved complete relief of symptoms and improvement in quality of life scores.To compare the incidence of adverse effects/drop-outs (total number for each drug) associated with the different treatments.To assess the proportion of participants in whom successful eradication was achieved. SEARCH METHODS: In this update, we identified trials by searching the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (1950 to March 2016) and Ovid EMBASE (1980 to March 2016). To identify further relevant trials, we handsearched reference lists from trials selected by electronic searching, and published abstracts from conference proceedings from the United European Gastroenterology Week (published in Gut) and Digestive Disease Week (published in Gastroenterology). The search was last updated in March 2016. We contacted members of Cochrane Upper GI and Pancreatic Diseases, and experts in the field and asked them to provide details of outstanding clinical trials and any relevant unpublished materials. SELECTION CRITERIA: We analysed randomised controlled trials of short- and long-term treatment of peptic ulcer disease in H. pylori-positive adults. Participants received at least one week of H. pylori eradication compared with ulcer healing drug, placebo or no treatment. Trials were included if they reported assessment from two weeks onwards. DATA COLLECTION AND ANALYSIS: We collected data on ulcer healing, recurrence, relief of symptoms and adverse effects. We calculated the risk ratio (RR) with 95% confidence intervals (CI) using both fixed-effect and random-effects models with Review Manager software (RevMan 5.3) based on intention-to-treat analysis as far as possible. MAIN RESULTS: A total of 55 trials were included for one or more outcomes for this review.In duodenal ulcer healing, eradication therapy was superior to ulcer healing drug (UHD) (34 trials, 3910 participants, RR of ulcer persisting = 0.66, 95% confidence interval (CI) 0.58 to 0.76; 381/2286 (adjusted proportion: 12.4%) in eradication therapy plus UHD versus 304/1624 (18.7%) in UHD; low quality evidence) and no treatment (two trials, 207 participants, RR 0.37, 95% CI 0.26 to 0.53; 30/125 (adjusted proportion: 21.7%) in eradication therapy versus 48/82 (58.5%) in no treatment; low quality evidence).In gastric ulcer healing, the differences were imprecise between eradication therapy and UHD (15 trials, 1974 participants, RR 1.23, 95% CI 0.90 to 1.68; 220/1192 (adjusted proportion: 16.0%) in eradication therapy plus UHD versus 102/782 (13.0%) in UHD; very low quality evidence). In preventing duodenal ulcer recurrence the differences were imprecise between maintenance therapy with H.pylori eradication therapy and maintenance therapy with UHD (four trials, 319 participants, RR of ulcer recurring 0.73; 95% CI 0.42 to 1.25; 19/159 (adjusted proportion: 11.9%) in eradication therapy versus 26/160 (16.3%) in UHD; very low quality evidence), but eradication therapy was superior to no treatment (27 trials 2509 participants, RR 0.20, 95% CI 0.15 to 0.26; 215/1501 (adjusted proportion: 12.9%) in eradication therapy versus 649/1008 (64.4%) in no treatment; very low quality evidence).In preventing gastric ulcer recurrence, eradication therapy was superior to no treatment (12 trials, 1476 participants, RR 0.31, 95% CI 0.22 to 0.45; 116/697 (adjusted proportion: 16.3%) in eradication therapy versus 356/679 (52.4%) in no treatment; very low quality evidence). None of the trials reported proportion of people with gastric ulcer not healed after initial therapy between H.pylori eradication therapy and no active treatment or the proportion of people with recurrent gastric ulcer or peptic ulcers during maintenance therapy between H.pylori eradication therapy and ulcer healing drug therapy. AUTHORS' CONCLUSIONS: Adding a one to two-week course of H. pylori eradication therapy is an effective treatment for people with H. pylori-positive duodenal ulcer when compared to ulcer healing drugs alone and no treatment. H. pylori eradication therapy is also effective in preventing recurrence of duodenal and gastric ulcer compared to no treatment. There is currently no evidence that H. pylori eradication therapy is an effective treatment in people with gastric ulcer or that it is effective in preventing recurrence of duodenal ulcer compared to ulcer healing drug. However, confidence intervals were wide and significant benefits or harms of H. pylori eradication therapy in acute ulcer healing of gastric ulcers compared to no treatment, and in preventing recurrence of duodenal ulcers compared to ulcer healing drugs cannot be ruled out.