Helicobacter pylori is associated with various gastroduodenal diseases such as peptic ulcer, functional dyspepsia, MALT lymphoma and distal gastric cancer. Diagnosis of H. pylori can be established by non-invasive ((13C)urea breath test, stool antigen test, serology) and invasive (histology, rapid urease test, culture) tests. In adults, culture and susceptibility testing should or must be performed after failing of first-line therapy in case of a control endoscopy and before third-line therapy, respectively. Peptic ulcer and gastric MALT lymphoma represent obligatory indications for eradication therapy. Other potential indications are functional dyspepsia, prevention of gastric cancer in individuals being at risk, and before starting treatment with traditional non-steroid antiphlogistics. First-line therapy is performed with a 7-days combination of proton pump inhibitor with clarithromycin and amoxicillin or metronidazole. In second-line therapy levofloxacin and rifabutin are good rescue antibiotics.