The rarity of primary tumor of the trachea, which was recently estimated in a circumscribed population to be 2.7 new cases per million per year, explains the relatively limited experience that has been acquired even by major institutions. Although there may already by a high degree of airway obstruction, tracheal tumors are usually misdiagnosed as bronchial asthma or chronic bronchitis because of its nonspecific symptoms. Surgery is the treatment of choice. Recently, the authors experienced three cases of primary tracheal malignant tumors ; one case of mucoepidermoid carcinoma and two cases of adenoid cystic carcinoma. The authors report on these cases with a review of the literature for give help in differential diagnosis and treatment planing of tracheal tumor.