Tardive dyskinesia. Tardive dyskinesia is a potentially irreversible syndrome of involuntary hyperkinetic movements that occur in predisposed persons receiving extended neuroleptic (antipsychotic) drug therapy. It is usually characterized by choreoathetoid dyskinesias in the orofacial, limb, and truncal regions, but subtypes of this syndrome may include tardive dystonia and tardive akathisia. Although the mechanisms underlying the pathogenesis and pathophysiology of this disorder are unproven, altered dopaminergic functions will likely play a role in any explanation of it. Tardive dyskinesia develops in 20% of neuroleptic-treated patients, but high-risk groups such as the elderly have substantially higher rates. Risk factors include age, female sex, affective disorders, and probably those without psychotic diagnoses, including patients receiving drugs with antidopaminergic activity for nausea or gastrointestinal dysfunction for extended periods. Total drug exposure is positively correlated with tardive dyskinesia risk. Management strategies include a careful evaluation of both the psychiatric and neurologic states, a broad differential diagnosis, and adjustment of neuroleptic agents to the lowest effective dose that controls psychosis and minimizes motor side effects. No drug therapy is uniformly safe and effective for treating this disorder. A favorable long-term outcome of improvement or resolution correlates with younger age, early detection, lower drug exposure, and duration of follow-up. 