Mucoepidermoid tumors of the bronchial tree are uncommon neoplasms, which are believed to arise from ductular epithelium of glands of the proximal tracheobronchial trees. For the 3 decades since their description, the clinical features, optimum treatment, and prognosis have become progressively clearer. Most investigators agree that the tumors have a favorable course, but others have reported cases in which apparently low-grade mucoepidermoid tumors were highly aggressive and associated with a poor prognosis. We report the case of an unusual low-grade mucoepidermoid tumor which arose peripherally to metastasize to the bilateral lungs of a 78-year-old woman. Literature concerning the diagnosis and management of mucoepidermoid tumors of the lung is also reviewed.