Objective: To evaluate the clinicopathologic features of pediatric mucoceles diagnosed in two public institutions in Brazil during an 18-year period. Method and Materials: Clinical data (age, sex, history of trauma, location, and size) of 138 cases of mucoceles in children 0 to 16 years of age were obtained from medical records. The lesions were classified as mucus extravasation phenomenon and mucus retention phenomenon, depending on the presence of epithelial lining in the microscopic analysis. Results: Mucoceles made up 24.5% of the oral pediatric lesions diagnosed in the period of study. Age at diagnosis ranged from 0.4 to 16.0 years, with a mean age of 10.8 years. Of the total of mucoceles, 87 were observed in females and 51 in males. The lower lip was the most commonly affected site, and a history of trauma was related by 87% of the patients. Histologically, 96.4% of mucoceles were diagnosed as mucus extravasation phenomenon. Cases of mucus retention phenomenon were relatively more common in the floor of the mouth, since one in three lesions in this location belonged to this histologic type. Regarding lesions in the lower lip, only 2.65% were diagnosed as mucus retention phenomenon. Conclusion: Trauma is the main etiologic factor involved in the development of mucoceles in children. The mucus extravasation phenomenon is the most common histologic type in this age group. Although rare, the retention type seems to be more common in lesions on the floor of the mouth. Keywords: minor salivary glands, mucoceles, mucus extravasation cyst, mucus retention cyst, pediatric population, ranula