Helicobacter pylori is recognized to be a serious pathogen, but there is still controversy as to who should be treated. There is consensus for treatment of Helicobacter-positive peptic ulcer and B-cell lymphoma. Lymphocytic gastritis and giant-fold gastritis (Ménétrièr's disease) may also respond to treatment. Patients with func-tional dyspepsia have a 20% placebo response with a 5-10% 'eradication' response, results not dissimilar from empirical treatment with a proton pump inhibitor. A 'test and treat' policy for patients with uninvesti-gated dyspepsia remains controversial. Some have suggested that eradication may increase the risk of GERD, or predispose to adenocarcinoma at the gastro-oesophageal junction. However, PPI treatment without Helicobacter eradication induces greater inflammation in the gastric corpus, the phenotype associated with non-cardia gastric cancer. A minority believe that Helicobacter should be eradicated in all individuals. When choosing treatment it is logical to start with a combination of antibiotics that, in the event of failure, will allow a second combination to be used without overlap.