Tardive dyskinesia is now widely recognised as a neurological disorder associated with the administration of antipsychotic drugs. Prevalence is higher among the elderly. The cause is unknown but the hypothesis of hypersensitivity of post-synaptic dopamine receptors is currently generally accepted. Many therapeutic approaches have been suggested but there is no completely satisfactory treatment at present. The main purpose of this study was to undertake a survey of the prevalence of the disorder in a sample of elderly subjects who were resident in local authority homes for the elderly, and to determine what drugs were associated with the condition. A total of 500 elderly subjects were examined for dyskinetic movements and a prevalence rate of 15 per cent was identified. Association of. tardive dyskinesia with antipsychotic agents, antiparkinsonian agents and the benzodiazepines was investigated. Preliminary work to the main subject included an evaluation of the various rating procedures, followed by a pilot study in a group of long-stay mental handicap patients. Following earlier reports of the success of co-dergocrine in treating tardive dyskinesia, a double-blind study was carried out in a group of 43 patients who had been hospitalised for many years and in whom the disorder was firmly established. The implications for psychiatry of tardive dyskinesia are discussed and the current practices for management of the syndrome are considered. Research strategies are reviewed and, finally, recommendations are made for both the strategy to limit the incidence of tardive dyskinesia and the management of the problem if it arises.