The thyroglossal cyst is the most common nonodontogenic cyst in the neck. This cyst may also occur in the lingual or submental areas, though more rarely. Malignant changes have been described. Clinically, no differentiation between a benign cyst and a malignancy can be made. The literature is reviewed regarding the embryology, epidemiology, etiology, symptomatology, radiology, histology, and treatment of this cyst and its malignant counterpart.