In recent years concern has been frequently expressed that a long-term treatment with fluspirilene 1.5 mg/week might induce tardive dyskinesia, yet there are no empirical data from controlled studies available. In 11 private practices 276 patients under long-term treatment with either fluspirilene or benzodiazepines for reasons of anxiety or psychoneurotic or psychosomatic disorders were investigated by an independent and specially trained physician from our hospital with regard to symptoms to tardive dyskinesia, parkinsonism, and akathisia. Of these patients, 155 had received fluspirilene 1.5 mg/week with a mean duration of treatment of 17.5 months (s = 13.3), and 121 had received benzodiazepines with a mean duration of treatment of 45.7 months (s = 44.6). The mean total scores of the AIMS, the Simpson Angus Scale, and an akathisia scale did not differ significantly between the two groups. In the fluspirilene group a positive correlation of age and psychotropic comedication with the total scores of the AIMS and the akathisia scale could be found, but there was no correlation between duration or continuity of treatment with fluspirilene and symptoms of tardive dyskinesia. In each of the two groups 10 patients (6.9% of the fluspirilene group and 8.3% of the benzodiazepine group) showed abnormal involuntary movements, which corresponds to the incidence of spontaneous dyskinesia. The results of this study do not indicate an increase in tardive dyskinesia for patients with a mean duration of treatment with fluspirilene 1.5 mg/week of 18 months.