A prerequisite for rational antibiotic treatment is the suspicion that the disease is caused by bacteria and that treatment will reduce symptoms and complications. In primary health care most infections are caused by bacteria. The European project HAPPY AUDIT found that an intervention targeting doctors and patients in primary care led to a considerable decrease in antibiotic prescribing. Teaching of hospital doctors, combined with a restriction in the choice of antibiotics, resulted in a decrease in multidrug-resistant strains. A concerted effort is needed to curb the growing resistance problem.