Respiratory tract infections are the most common indication for antibiotic prescribing in primary care. Several studies have shown a strong relationship between antibiotic use and bacterial resistance. The aim of this trial was to assess the long-term effect of a continuous education program on general practitioners antibiotic prescribing behaviour. 170 physicians were included in this study. Physicians randomized in the education group attended a two days seminar focused on evidence-based guidelines on antibiotic use in respiratory tract infections. The intervention was limited at physicians level and did not target the patients.