Two sporadic cases of striato-nigral degeneration were characterized by the onset at the age of 61 of an akinetic-hypertonic syndrome and of a minimal or absent rest tremor, with a pyramidal syndrome, sphincter disorders, dysphonia, difficulty in swallowing and an unfavorable development in the space of two or three years not affected by L-Dopa. In one case, total insomnia was demonstrated by means of 3 polygraphic recordings during the night, two of them consecutive, and aprobenecide test showed a definite fall in H.V.A. and 5 H.I.A.A. in the lumbar cerebrospinal fluid. Anatomical verification showed, in one case, isolated putamino-nigral degeneration, and in the other associated with lesions of the olivo-cerebellopontine system. Much of the excess pigmentation found only in the putamen was melanotic in character and resulted perhaps from the striato-nigral degeneration, making it possible to classify this more accurately among the other multisystem degenerations, especially olivo-ponto-cerebellar atrophy and Shy-Drager syndrome