Mucoepidermoid carcinoma was initially recognized as occurring only in the salivary gland and only later was it appreciated that it occurred in the bronchus and trachea as well. Mucoepidermoid carcinoma of bronchial gland origin is extremely rare, and little is known about their natural history. This carcinoma is derived from the minor salivary gland of the proximal tracheobronchial tree and it is divided into low-grade and high-grade by gross, histologic, and ultrastructural criteria. Also its clinical and biologic behaviors are closely related with histologic grade of carcinoma. We have experienced a rare case of bronchial mucoepidermoid carcinoma associated with adenocarinoma which obstructed the left main bronchus and was successfully removed by the pneumonectomy.