Epignathus is an extremely rare, benign, congenital teratoma that arises from the oral cavity. When treating epignathus with cleft palate, it is particularly important to consider velopharyngeal function and maxillary growth after surgical repair. The case of an infant with a complete cleft palate and a large mass, histologically diagnosed as a mature teratoma, that protruded from the right soft palate is described. At 8 months of age, a double-opposing Z-plasty was performed using a part of the tumor over the right soft palate that had been left at the time of primary excision at 3 months of age for an epignathus protruding from the mouth. Though all that could be done was suture tumor tissue on the right side and the left hypoplastic levator veli palatine muscle using the double-opposing Z-plasty, velopharyngeal function and maxillary growth were good at 10 years of age.