There are few studies on pediatric oral pathologies in the literature. This study presents data from a review of 2,356 biopsies of young patients (birth to 14 years) received over 15 years (1985-2000) in the Oral Pathology Service at the University of Sao Paulo, Brazil. Information about patients (sex, age, race) and histopathological diagnosis was retrieved. Diagnosis data of 2,356 biopsies were classified into 20 groups. There was no significant difference between male (50.0%) and female (49.0%) patients. White is the predominant race (69.0%), and patients ages were concentrated between 9 and 14 years old (70%). Mucocele was the most frequent (13.5%), followed by dentigerous cyst (6.5%) and fibrous hyperplasia (5.4%). Papilloma and Langerhans cells histiocytosis were the most common non-odontogenic benign and malignant tumors, respectively. In the group of odontogenic tumors, odontoma was the most frequent, and ameloblastoma had a significant incidence (27 cases). These data are important in order to detect differences in geographic areas, diagnosis line tendencies and for clinicians to perform judgment to evaluate of the pediatric patients before the biopsy and management of pediatric oral lesions.