This research work was done with the following aims: a) to describe a random sample of public schools (5 to 8 high school series), failure, changing school and activities to cover deficiencies; and b) to collect data and to analyse how effective is the assertion that failure is done within the classroom. Aiming to answer these questions, we took randomly 238 pupils of 45 classes of 6 public schools, in a midland city of São Paulo State. Our main data show that: 25% pupils fall in course of four final series of high school and 16% leave school in this same period; the variables studied did explain a sugnificative amount of the school failure; according the theoretical model used, the most decisive element of pupil's failure occurs really within the classroom itself.
