Objective: About 20 percent of patients receiving long-term treatment with neuroleptic medications develop tardive dyskinesia. A 1988 review of treatment studies for the disorder found that 40 percent of patients showed at least 50 percent improvement in symptoms. This paper reviews studies published since 1984, including those not reviewed in 1988, to learn whether new or improved treatments for the disorder have been developed. Methods: Twenty-five open, blind, or double-blind studies (with a minimum of five patients) published between 1984 and May 1992 were examined. The studies involved neuroleptics, including clozapine, dopaminergic and dopamine-depleting agents, GABA-ergic drugs, vitamin E, calcium channel blockers, and adrenergic drugs. Results and conclusions: Overall, only 26 percent of patients who participated in the studies reviewed had a 50 percent or greater reduction in symptoms. The authors conclude that treatment of tardive dyskinesia remains a highly individual process and recommend that future studies be more carefully designed.