ABSTRACT:Studies assessing the prevalence of oral lesions show that 5.2% to 12.8% of biopsy specimens are from children and adolescents. In Brazil, there are few studies analyzing the distribution of oral lesions in that population. Therefore, the aim of this study was to evaluate the distribution of oral and maxillomandibular lesions of adolescents, admitted to the Department of Oral Diagnosis of the Federal University of Paraná (UFPR) from 1994 to 2013. A study based on the review of the charts was done and the lesions were classified in 11 categories: salivary glands disease, dental pathology, gingival and periodontal pathology, odontogenic cysts, odontogenic tumors, non odontogenic cysts, bone pathology, mucosal pathology, connective tissue pathology, malignant tumors and other pathology. Variables including age, sex, ethnicity, diagnosis and lesion location were also evaluated. Upon analysis, 376 lesions were identified, most in girls, 51.9% and 77.1 % of patients were white. The most frequent site was the lower lip followed by the gingiva. Mucocele was the most common lesion (27.6%), followed by fibroepithelial hyperplasia (8.2%) and pyogenic granuloma (5.3%). Although there is a wide range of pathologies that can occur in the oral cavity, traumatic injuries are the most common in this age group.