The study dealt with the occurrence of dyskinetic symptoms and disturbances in eye movements in 15 young schizophrenic patients and the effect on these disturbances of anticholinergic antiparkinsonian medication administered during neuroleptic medication maintained at a stable level. The onset of illness had occurred at a younger age in the dyskinetic patients than in the others, and they had received larger amounts of high-dose neuroleptic medication, which, however, equalled an average daily dose of only 331 mg of chlorpromazine during an average of 2 1/2 years; thus, dyskinetic symptoms can appear in young patients even during a fairly short and moderate course of medication with high-dose neuroleptics. Patients with a disturbance in smooth pursuit movement were clinically less disturbed than the others; depression, however, was more common among them. During therapy with an anticholinergic antiparkinsonian drug (Biperiden) depression worsened in patients with eye movement disturbance, while in other patients it was alleviated. The results, in fact, indicated that on the basis of disturbances in smooth pursuit movement it might be possible to distinguish among schizophrenia-group patients a depressively coloured marginal group in whom the reaction to anticholinergic medication differs from that found for patients in the nuclear-schizophrenia group.