Because of evidence of causal association between antibiotic use and bacterial resistance, the implementation of national policies has emerged as a interesting tool for controlling and reversing bacterial resistance. The aim of this study was to assess the impact of public policies on antibiotic use in Europe using a differences-in-differences approach. Comparable data on systemic antibiotics administered in 21 European countries are available for a 11-year period between 1997 and 2007. Data on national campaigns are drawn from the public health literature. We estimate an econometric model of antibiotic consumption with country fixed effects and control for the main socioeconomic and epidemiological factors. Lagged values and the instrumental variables approach are applied to address endogeneity aspects of the prevalence of infections and the adoption of national campaigns. We find evidence that public campaigns significantly reduce the use of antimicrobials in the community by 1.3-5.6 defined daily doses per 1,000 inhabitants yearly. This represents an impact of roughly 6.5-28.3 % on the mean level of antibiotic use in Europe between 1997 and 2007. The effect is robust across different measurement methods. Further research is needed to investigate the effectiveness of policy interventions targeting different social groups such as general practitioners or patients.