The article deals with the discursive regularities of free education existing in the Constitutions of Brazil and Mexico, more specifically in the Constitution of the Federative Republic of Brazil of 1988, as well as in the Political Constitution of the United Mexican States of 1917, and their effects on rates of literacy. The analysis necessarily passes through the notes of the concepts disseminated by Michel Foucault in his work Archeology of Knowledge (2008). Bibliographic and documental research was carried out with the comparative method, which constitutes an important instrument of analysis, respecting the historical specificities and the real materiality of each of the countries. The deductive and hypothetical-deductive method was also used in the elaboration of the comparative analytical study and collection of statistical data provided by the UNESCO Institute for Statistics (2021). It is concluded that there is a continuity in the expressive dispersion of statements tending to free education in the constitutional texts of Brazil and Mexico, revealing the existence of discursive regularities that are continuous, due to the materialization of the constitutional discourse in each nation, triggering the growth of rates literacy in both countries.