This article is part of the discussions about external evaluation systems at the municipal level. The objective was to compare the results of municipal schools in the Prova São Paulo, a large-scale external evaluation of the network itself, with those obtained in Prova Brasil, between 2007 and 2012. Through a comparative quantitative study of the average proficiency of students in the 5th and 9th grades, in Portuguese and Mathematics, from 435 schools, it was verified a disparity between the results in Prova Sao Paulo when compared to Prova Brasil. It is concluded that large-scale external evaluations at local level are important instruments for the establishment of public policies that, on the one hand, require meta-evaluation mechanisms, in order not to jeopardize the instrument itself. On the other side, it is necessary not to assign responsibility for such results only to schools and their actors, leaving aside the role of the State as responsible for public education of quality.