The school food environment is a suitable place to promote healthy habits, as it is a space for learning and constant social interaction, where children spend at least a third of their day, and have one to two meals. This study aimed to analyze the sale of food in the canteens of private schools in a capital in the Northeast of Brazil and verify the influence of it on students’ eating behavior. A cross-sectional, quantitative, multicenter study was carried out, taking place simultaneously in twenty capitals in Brazil. A checklist with 87 questions was applied to those responsible for the canteens in a representative sample of schools in each city. Frequencies and associations were performed using Pearson's Chi-Square test. The analysis of the foods sold, was based on the NOVA food classification from the Dietary Guidelines for the Brazilian Population, regarding the degree and extent of processing. Latent Class Analysis was carried out to group the canteens into similar response patterns, modeled with covariates, and the association was calculated with the Kruskal-Wallis and Duun tests or Fisher's Exact test. The results showed that students were very frequently offered ultra-processed, sugar-rich foods with low nutritional value; 88.7% of such foods had been chosen by managers as part of the menu because they are “students’ food preferences”. There is an average of 2.3 fresh foods in canteens compared to 7.5 varieties of ultra-processed foods. There must be stricter control over what is sold, to minimize student’s exposure to unhealthy foods.