Pig farmers are strongly encouraged to reduce their antimicrobial usage in order to reduce the risk ofantimicrobial resistance. Herd-level intervention is needed to achieve national and European reduc-tion targets. Alternative, especially preventive measures, have to be implemented to reduce the needfor antimicrobial treatments. However, little is known about the feasibility, effectiveness and return oninvestment of such measures. The objective of this study was to assess, across four countries, the tech-nical and economic impact of herd-specific interventions aiming at reducing antimicrobial usage in pigproduction while implementing alternative measures.An intervention study was conducted between February 2014 and August 2015 in 70 farrow-to-finishpig farms located in Belgium, France, Germany and Sweden. Herd-specific interventions were definedtogether with the farmer and the herd veterinarian. Farms were followed over one year and their antimi-crobial usage and technical performance were compared with values from the year before intervention.Compliance with the intervention plan was also monitored. Changes in margin over feed cost and net farmprofit were estimated in a subset of 33 Belgian and French farms with sufficient data, using deterministicand stochastic modeling.Following interventions, a substantial reduction in antimicrobial use was achieved without negativeimpact the overall farm technical performance. A median reduction of 47.0% of antimicrobial usage wasachieved across four countries when expressed in terms of treatment incidence from birth to slaughter,corresponding to a 30.5% median reduction of antimicrobial expenditures. Farm compliance with inter-vention plans was high (median: 93%; min-max: 20; 100) and farms with higher compliance tended toachieve bigger reduction ( = -0.18, p = 0.162). No association was found between achieved reduction andtype or number of alternative measures implemented. Mortality in suckling piglets, weaners and fatten-ers, daily weight gain and feed conversion ratio did not significantly change over the course of the study,while the number of weaned piglets per sow per year slightly increased. The median change in net farmprofit among Belgian and French farms was estimated to be D 4.46 (Q25-Q75:-32.54; 80.50) and D 1.23(Q25-Q75:-32.55; 74.45) per sow per year using the detererministic and stochastic models, respectively.It was more influenced by a change in feed conversion ratio and daily weight gain than by a changein antimicrobial expenditures or intervention direct net cost. Therefore, costs of alternative measuresshould not be perceived as a barrier, but rather as an opportunity to optimise production practices forsustained productivity and improved animal health.