This study examines to what extent there is a sort of "political appropiation" by political parties when they seek to set a discourse about the Spanish PISA outcomes. We have consistently found that programs for assessing the competencies of students, especially PISA, have become tools of rationalization and the legitimization of education policies in both the national and territorial contexts. Furthermore, each regional government focuses its discourse on what it feels to be its strong points, that is, a clear "self-justifying reading" of PISA outcomes.