Tardive dystonia is a difficult condition to treat. We describe the case of a patient with tardive dystonia that was unresponsive to various pharmacological and electroconvulsive therapies. The patient showed dramatic improvement after the administration of eperisone, a centrally acting muscle relaxant. Eperisone and tolperisone are beta;-aminopropiophenone derivatives which are used clinically as antispastic agents. To date there have been no reports describing the effect of such muscle relaxants on tardive dystonia. The results of our study suggest that these muscle relaxants may be promising therapeutic drugs for the treatment of tardive dystonia.