A bronchial mucoepidermoid tumor in a 13-year-old female was studied by light and electron microscopy. This is the seventh reported case of this rare bronchial neoplasm in a person less than 16 years of age and the only case, in any age group, which has been studied ultrastructurally. All reported cases of bronchial mucoepidermoid tumors in childhood have been histologically of the low grade (well differentiated) variety with a benign clinical course. Although there are histological features which distinguish this lesion from the even rarer bronchial mucous gland adenoma, the clinical features and biological potential of the two lesions in this age group appear to be identical. The optimal surgical therapy for bronchial mucoepidermoid tumors and mucous gland adenomas, when occurring in children, is identical. There must be total removal of either lesion with the sacrifice of as little normal lung as possible. When technically possible, a sleeve resection of the involved bronchus is recommended; however, in most cases, the location of the lesion requires a lobectomy for complete removal.