Breat hing represents one of the vital functions of the organism, and its unbalance causes some series of alterations in several organs and systems. Aim: Verify the influence of socio-economic and demographic factors in determining breathing patterns. Study design: cross-sectional. Materials and Methods: there were 143 students in the sample, with ages ranging from 9 and 10 years, from two schools, public and private, in the city of Recife, Pernambuco. Breathing patterns were established through two tests: Glatzel Plate (Steam) and water time in the mouth. Socio-economic factors were evaluated through questionnaires with nine questions each. Statistics were carried out by means of the ChiSquared test or Fisher's Exact test and the significance level used was of 5%. Results: Oral breathing prevalence was of 55.2%, higher among females (57.7%) and in public schools (67.2%).Lack of medical care (62%), less use of medications (56.6%), parents with educational levels lower than high school, divorced parents (66%), students that do not live with their parents (68.7%) and homes with only one room (72%), in all of those situations, oral breathing signs were more prevalent. Only school type had significant association with the breathing pattern. Conclusion: High levels of oral breathing without differences concerning gender and age. With the exception of school type, there was no association between breathing pattern and socio-economic factors.