Helicobacter Pylori (H. Pylori) is the primary cause of duodenal ulcer (DU). Guidelines recommend that all patients with DU be considered for Helicobacter Pylori Eradication Therapy (HPET). However, the proportion of patients with DU on long term anti-ulcer medication receiving HPET is small. This study examined the effectiveness of the continuing medical education (CME) network of the Irish College of General Practitioners (ICGP) in promoting best practice in DU treatment among GPs in an eastern region of Ireland. Ninty eight GPs recruited from the CME network of the ICGP were randomised in two cohorts. Cohort 1 received an (early) intervention; GPs were asked to identify their patients with DU receiving long term anti-ulcer medication and prescribe HPET according to defined criteria. Cohort 2 received the intervention later. Prescribing of HPET was monitored using routine prescribing data. Twenty per cent (286/1,422) of patients in cohort 1 and 19.2% (127/661) in cohort 2 had a DU. After exclusions, 53% (152/286) in cohort 1 and 30.7% (39/127) in cohort 2, were eligible for HPET. A significantly higher proportion of patients in cohort 1 received HPET compared with cohort 2 during the early intervention period (13.8% vs 0.0%, p<0.05). Reasons for not prescribing HPET included concurrent illness in patients, failure to comply with treatment. Best practice guidelines on HPET treatment of DU can be successfully applied using CME networks. This model could be repeated in another therapeutic area where established research is not yet current practice.