21 patients with diagnosis of idiopathic OPCA were examined clinically and evaluated by MRI or CT-scan. On the basis of Quinn's criteria for MSA, patients were subdivided into those with probable MSA (48 p. cent) and those with possible MSA (52 p. cent). Median age at onset was 51.8 years. The initial clinical feature of the disease was ataxia, but the presence of multiple system involvement was clear in all cases. The combination of involvement of four different system (cerebellar, parkinsonian, pyramidal, autonomic) was the most common (28.5 p. cent), followed by the association of cerebellar and pyramidal features (24 p. cent). Autonomic symptoms were present in 48 p. cent of patients. CY-scan or MRI showed cerebellar and brainstem atrophy in 43 p. cent of cases. There was no relation with the duration of the disease or the severity of clinical features. Moreover brainstem auditory evoked response and EMG were not helpful in diagnosis.