INTRODUCTION: The malocclusion, due to its high prevalence in the population is currently considered a public health problem. Considering the association between oral habits and malocclusion, knowledge of the epidemiology of occlusal alterations in children with non-nutritive sucking can contribute to the establishment of public policies. OBJECTIVE: To assess the prevalence of malocclusion in children in primary dentition phase with deleterious habits of finger sucking and/or pacifier. MATERIAL AND METHOD: The study involved 135 children of both genders, aged 3-6 years, with non-nutritive sucking habits. The history of finger sucking and/or pacifier was raised by a questionnaire given to parents and guardians. Clinical assessment of malocclusion was performed by a single examiner previously calibrated in order to minimize possible errors of the method. RESULT: Malocclusion was found in 87.4% of children. There was a 72% prevalence of anterior open bite, followed by maxillary atresia with 62.2%, posterior cross bite with 26.3%, anterior cross bite with 3.4%, crowding and top-to-end corresponding to 5.1% of the sample. The most common harmful habit was the pacifier-sucking, present in 76.3% of the sample, while the same was distributed as follows: 20% in the isolated, 25.9% associated with other deleterious habits, 3% associated the finger, 26.7% associated with bottle and 0.8% associated with finger and bottle. Already finger sucking was found in 25.9% of the sample, 14.1% in isolation. CONCLUSION: Children with nonnutritive sucking during the deciduous dentition show a high prevalence of malocclusion. No statistically differences were found between genders and age groups in relation to malocclusion type and habit.