This text begins discussing the old issue of the educational statistics quality and some methodological aspects related to their use in educational research. It then analyses illiteracy focusing on: a) its emergency as a political problem at the end of the Brazilian Empire; b) the evolution of this concept; c) the long term trend, both in relative and absolute numbers, from the first 1872 Census to the last one, in 2000. Finally, based on the 2000 Census, it classifies the population according to their different levels of literacy.
Illiteracy; Literacy levels; Demographic censuses; Brazil
