Ankyloglossia (tongue-tie) is a congenital anomaly with a prevalence of 4-5% and characterized by an abnormally short lingual frenulum. For unknown reasons the abnormality seems to be more common in males. The pathogenesis of ankyloglossia is not known. The author reports a family with isolated ankyloglossia inherited as an autosomal dominant trait. The identification of the defective gene(s) causing ankyloglossia might reveal novel information on the craniofacial embryogenesis and its disorders.