This article reviews oral form and function interactions pertinent to tongue thrust and provides guidelines for selecting cases and planning treatment. Anterior tongue positioning during speech and swallowing, commonly called tongue thrusting, is seen in about 50% of normal eight-year-old children. Open bite malocclusion, the most frequent related dental problem, occurs in about 4%. Both percentages decline with advancing years. Certain anatomical conditions, particularly related to pharyngeal airway dimensions, predispose normal children to anterior tongue positioning which disappears during puberty. In these children, the tongue thrust is a normal, if delayed, transition stage. In other children, it is a necessary adaptation. Swallowing therapy is not indicated in the absence of speech or dental problems, and, in our view, is not indicated before puberty. If tongue thrust and an associated malocclusion persist to puberty, swallowing therapy may be indicated. The therapy then is most effective when combined with orthodontic treatment to reposition teeth, rather than preceding orthodontic treatment. Articulation therapy techniques involving phonetic placement may be particularly helpful in modifying speech errors in tongue thrusters while also repositioning the tongue tip posteriorly.