In a series of 50 patients, 94 stereotactic lesions involving different parts of the dentate nuclei of the cerebellum were performed. 47 patients exhibited various dyskinetic syndromes; among these, 7 were also affected by epilepsy. In 3 patients epileptic disorders were exclusively present. Favourable results were obtained in dystonic and dystonic-athetoid infantile syndromes, more than in spastic syndromes. Some interesting effects on the epilepsy and ocular motility are also noted.