This study compares the cost effectiveness of Helicobacter pylori eradication and conventional treatment in duodenal ulcer patients treated by a general practitioner. Using a Markov chain approach, Swedish cost data and a study period of 5 years, we conclude that H. pylori eradication with omeprazole and appropriate antibiotics is a cost-effective alternative compared with both maintenance and episodic treatment. Of the patients entering the eradication strategy, most are cured and will have no relapse during a 5-year period. H. pylori eradication results in higher initial costs but, because of a very low risk of recurrence after successful eradication, the expected future costs are reduced. The investment pays off within 1 year when compared with maintenance treatment, and within 3 years when compared with episodic treatment.