Dystonia is the result of abnormal contractions of muscles, which may disturb activities between agonist and antagonist muscles. Since synchronization of laryngeal and masticatory muscles is highly necessary to allow opening and closure of the larynx or the mouth, expression of dystonia is especially exhibited. Focal laryngeal dystonia may disturb phonation, but also breathing or swallowing, which may be difficult to identify. In ORL, the botulinum toxin is used to treat focal dystonias, especially laryngeal (spamodic dysphonia being predominant) and oromandibular dystonias. Beside these indications, intracutaneous injections of botulinum toxin may be helpful in Frey's syndrome in patients with gustatory sweating; injections in the upper esophageal sphincter are also performed in cricopharyngeal dysphagia although this indication is mainly controversial.