Dermoid cysts of the oral cavity are extremely rare. The most common site is the floor of the mouth whereas intralingual location is the most unusual. They may be congenital or acquired and according to their histological appearance they are distinguished in "true" dermoid, epidermoid or teratoid cysts. We present the clinical and radiographic findings of a large congenital intralingual "true" dermoid cyst in a 10-month-old boy. The large size of the lesion and the subsequent enlargement of the tongue caused difficulties in swallowing and sleeping, symptoms which subsided after the surgical treatment. The uncommon location, the large size and the very young age of the patient were the noteworthy parameters
