A dermoid cyst is a rare congenital midline neck mass with usually develops in the submental region. It is most often seen in young adults and can become rather large than almost no symptoms. As it increases in size, dysphasia, or dyspnea can develop. The differential diagnosis of the midline lesion includes ranula, thymglossal duct cyst, cystic hygroma, and cystic lymphangioma. The treatment of choice is complete surgical removal. With a review of the literature, we report two cases of a huge dermoid cyst inducing dyspnea.