Helicobacter pylori disposes of various virulence factors such as urease, vacuolating cytotoxin and the cag-pathogenicity island which--though not alone, but possibly in conjunction with host-specific factors--may explain the varying course of the infection (asymptomatic, dyspepsia, ulcer, distal gastric carcinoma). Increasing resistance to macrolide antibiotics and the lack of new therapeutic approaches makes treatment of the infection increasingly difficult. The resultant call for a strict indication for treatment is in obvious contrast to the finding that Helicobacter pylori represents the major risk factor for gastric carcinoma and eradication would therefore be absolutely desirable. Increased use of culture and susceptibility testing would be desirable for the purpose of therapy optimization but also for reasons of resistance epidemiology. The indication for diagnostic screening should be guided by the treatment indications as proposed by the guidelines of the Maastricht Consensus Conference 2-2000. In addition--and regardless of clinical picture--therapeutic follow-up primarily relying on non-invasive tests (13C urea breath test, stool antigen test) should be a matter of course.