Background: This paper aims at assessing the effectiveness of the package of road safety measures implemented after road safety was included in the political agenda in the year 2004 on the number of road traffic-injured people in Spain. Methods: An evaluation study was performed using an interrupted time-series design. The study population was people injured in road traffic crashes in Spain between 1 January 2000 and 31 December 2006. The road traffic crashes database of the General Directorate for Traffic was used. The dependent variable was the monthly number of people injured, stratified by sex, age, severity and type of road user. The explanatory variable (intervention) compared the post-intervention period (2004-6) with the pre-intervention period (2000-3). Quasi-Poisson regression models were adjusted, controlling for time trend and for seasonality. Results: Results show a reduction in the risk of being injured for both men (RR 0.91; 95% CI 0.87 to 0.95) and women (RR 0.89; 95% CI 0.85 to 0.94). Risk reductions were observed across all age groups and all road users, except for pedestrians. Conclusions: The present study suggests that prioritising road safety reduces the number of people injured in road traffic collisions., his work was supported by the Agencia Española de Tecnologías Sanitarias (Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+I) e Instituto de Salud Carlos III-Subdirección General de Evaluación y Fomento de la Investigación) (PI07/90157). The funding source has not had any involvement in the study design, in the collection, analysis and interpretation of data, in the writing of the report and in the decision to submit the paper for publication.