ABSTRACT Objective: to compare the parents and teachers views about the occurrence of deleterious oral habits in preschool children. Methods: a cross - sectional study with a quantitative analysis. Parents and teachers answered a self-administered questionnaire regarding the deleterious habits of preschool children and signed the Informed Consent Term. At the end, 221questionaries were included. The data were submitted to Chi-square test, Fisher exact and McNemar tests. Results: according to the parents, the most frequent habit was the bottle with 52.04%, followed by the pacifier with 24.09%. According to the teachers, the pacifier was the most frequent one, accounting for 20.36% of cases, followed by the use of bottle (7.69%). In the present sample, 90.95% of the children were breastfed. When related to oral habits, it was observed that the longer the breastfeeding time, the lower the use of pacifiers and bottles. By comparing the questionnaires, it was verified that the parents noticed, more frequently, the oral habits than did the teachers. Conclusion: in the group studied, the parents reported more the presence of deleterious oral habits than did the teachers. It is important that parents, and especially teachers, have information about the harm caused by the prolonged presence of such habits, so that they can encourage their interruption, thus, avoiding possible damages to the stomatognathic system and the performance of orofacial functions.