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Soon after the discovery of neuroleptics, neurological side effects of the extrapyramidal type were reported. The first description of neuroleptic-induced parkinsonism dates back to the "Swiss Symposium on Chloropromazine" held in 1953. Steck in 1954 vividly described the symptoms in a convincing manner. In 1955, Delay and Denicker, observing the therapeutic efficacy and extrapyramidal activity of two seemingly different compounds as chloropromazine and reserpine, used the term "neuroleptic" to characterize this common property. Two years later they proposed a definition of neuroleptics taking into account therapeutic efficacy as well as side effects. Such a definition was not accepted by American authors who preferred term like "major tranquilizers" and finally "antipsychotics". The meaning of neuroleptic parkinsonism (whether it was a side effect or part of the therapeutic action) had been discussed for a long time. The analogy with the clinical manifestations of Von Economo's encephalitis lethargica was also mentioned. Tardive dyskinesia appeared in the literature in the late 1950's. The first report was made by Schoenecker in 1957 who described bucco-oral movements persisting after the neuroleptics were diminished or discontinued. He concluded that these manifestations were different from the acute extrapyramidal side effects. Two years later Sigwald et al. reported involuntary movements of the tongue, lips and facial muscles which appeared after several years of phenothiazine treatment. In 1960 Uhrbrand and Faurbye described bucco-linguo-masticatory movements sometimes associated with trunk and foot movements. Half of these cases persisted (and a few aggravated) after neuroleptic withdrawal. In others the condition was unmasked by the neuroleptic discontinuation. In 1964 Faurbye et al. proposed the term "tardive dyskinesia" for this extrapyramidal side effect. After an initial description by Druckman et al. in 1962, the term of "tardive dystonia" was first used in 1973 by Keegan and Rajput. The patients described in the early literature were mainly of an advanced age with organic involvement. The first serious epidemiological studies were undertaken in the late 1960's, showing prevalences varying between 0.5 to 65%! Most of the predisposing factors suspected in early studies (cerebral lesions, lobotomy, ECT) were not confirmed in more recent studies that emphasized the role of an older age and a female gender. The interest in tardive dyskinesia varies from one country to another. Perhaps, dyskinesia was more severe and problematic in the USA because of more liberal indications for neuroleptic use, higher doses and smaller choice of neuroleptic medications. Medicolegal aspects have also increased the apprehension of american physicians. Tardive dyskinesia remains an enigmatic phenomenon and a therapeutic challenge. In the future, the possible discovery of antipsychotic molecules devoid of extrapyramidal side effects may discourage the research on these unresolved issues.