The aim of this article is to analyse the direct and indirect effects that PISA generates in the orientation of educational policies and reforms in Spain and the ways in which PISA data and results are used in political discourses, at both national and sub-national levels. The main hypothesis of the article is that PISA results have played a key role in shaping Spanish hegemonic educational discourses, policies and practices, setting the framework of what is "thinkable" and "doable" in education. To explore this hypothesis, the article identifies two main mechanisms that have become a regular recourse in national educational policy discourse--selectivity and instrumentalisation--providing several examples of their use in recent Spanish education reforms.