Population screening for H. pylori is likely to be cost-effective with a cost/LYS of under 10,000 GBP for the base assumptions, which compares favourably with other screening programmes. However the benefits take time to accrue and this cost/LYS is over an 80-year follow-up. Once-only screening at age 40 with a prevalent round for people aged 40-49 appears to be the most pragmatic policy. A major uncertainty is the effect of eradication of H. pylori on gastric cancer risk. The cost-effectiveness of H. pylori screening would be reduced if there were extensive H. pylori opportunistic testing of all dyspeptic individuals presenting to primary care.