Congenital teratoma is a rare condition and is a germ cell tumor composed of elements from one or more of the embryonic germ layers and contain tissues usually foreign to the anatomic site of origin. We report a case of a neck tumor diagnosed during pregnancy, initially thought to be a goiter. After birth the neck mass kept growing until it compressed the trachea and produced respiratory failure. The infant had a difficult tracheal intubation because of the compressing mass. The staff decided to surgically remove the neck mass. After that, the infant became eupneic. The histological analysis showed a mature teratoma with no atypias.