Since the APA's last report on tardive dyskinesia in 1979, considerable research has been conducted on the prevalence, incidence, and risk factors associated with the development of late occurring neuroleptic side effects. This report summarizes progress over the last decade in our understanding of the differential diagnosis and epidemiology of tardive dyskinesia, as well as risk factors, course, and treatment. Practicing clinicians should benefit from this report's discussion of indications for neuroleptic use, alternative maintenance strategies, factors to consider in making a differential diagnosis, frequently encountered problems in dealing with special populations such as children and the mentally retarded, clinical-recommendations for prevention and management.