The association between Helicobacter pylori and gastric and duodenal ulcer disease has presented new opportunities for the treatment of these disorders. Long-term suppression of acid secretion with H-2-receptor antagonists or proton pump inhibitors (PPIs) will keep patients in remission for as long as treatment is maintained but recurrence of symptoms occurs when the treatment is withdrawn. Recent studies have shown that eradication of H. pylori can reduce the risk of recurrence from 20-30% to just 5-10%. The regimens most widely used for successful eradication of H. pylori are seven-day triple therapies combining a PPI and two antibiotics; clarithromycin and metronidazole in Italy, clarithromycin and amoxycillin in France, and ro,roxithromycin and metronidazole in Germany. Once or twice daily dosing with lansoprazole (30 mg) as the PPI was found to be effective. If failure of triple therapy is confirmed by the C-13-urea breach test, quadruple therapy is recommended, combining a PPI, bismuth salt, metronidazole and tetracycline. The possibilities for future progress are based on an increased knowledge of the molecular biology of H. pylori and a better understanding of the expression of cytotoxicity and virulence factors of pathogenic strains. Preventive therapy through immunisation and vaccination is currently under investigation.