Introduction: the objective of this analysis was to determine the characteristics of occlusion in mouth breathing children, who are treated in the Child’s Clinic of the Faculty of Dentistry of the University of Antioquia. Methods: a cross-sectional descriptive study in 100 6-12 year old mouth breathing patients, who went for the first time to the Child’s Clinic (iv to vii semester), who had no prior therapeutic surgeries, identified with a checklist. Upon a medical examination, the following information was collected: socio-demographic variables, medical backgrounds, face features, oral habits, characteristics of the dental arches, occlusion related variables, and cavities and gingivitis. Results: over half the surveyed population is class i and did not show lip competence. Onychophagia and bruxism were other frequent habits. The lower dental midline deviated in respect of the face midline prevails in children (69%). As regards anterior crossbites, there were no significant differences between boys and girls; while the anterior open bite was more frequently found in children (26%). The oval shape of the arches was the most prevailing characteristic (higher: 85%, and lower 77%), and over half the patients showed to have high palate. Gingival inflammation signs were observed in 80%, and over 50% were found to have cavities. Conclusions: differential characteristics were found in the surveyed population, both face and occlusion characteristics, which require a deeper analysis for integral treatments based on the individual and collective needs.