The authors report an experiment undertaken with trazodone in the treatment of different forms of pathological involuntary movements. Forty-five subjects were treated for two months; 15 were affected with L-DOPA + decarboxylase inhibitor induced dyskinesias, 9 with choreic or choreoathetosic syndromes, 6 with primary buccolingual dyskinesias, 4 with ticks, 9 with tremors--3 of whom had delirium tremens--and 1 case of Wilson's disease with severe postural dystonia. At the end of treatment there was a considerable improvement in 40 cases (88.9%), 17 of whom (37.8%) had a reduction of over 65% of symptoms. The results were good in all the groups considered; particularly interesting were those obtained in delirium tremens, alcoholic induced tremor, primary buccolingual dyskinesias, L-DOPA + decarboxylase inhibitor induced dyskinesias. Emphasis is placed on the efficacy of the drug in inhibiting postural dystonia in the one case of Wilson's disease. The good tolerance of the drug was confirmed.