Primary adenocarcinoma of the oral cavity is an infrequently encountered problem. Adenocarcinomas are distinctive lesions which can be subclassified according to their tissue growth patterns or histomorphology. The polymorphous low-grade adenocarcinoma of the oral cavity is usually of minor salivary gland origin. We present an unusual case of polymorphous low-grade adenocarcinoma of the tongue and add this case to the existing two previous reports in the literature. A review of the current literature concerning this tumor is included. Treatment presently consists of complete local excision followed by radiation therapy.