Clinical evidences and experimental data on various signs and symptoms of autonomic dysfunction in idiopathic parkinsonism are reported and their characteristics related to the effects of the drugs usually administered for the therapy of the extrapyramidal symptoms. The use of instrumental diagnostic criteria may sometimes help to detect alterations of autonomic functions (micturition disturbances, disorders of pupil reactivity, orthostatic and postprandial hypotension, temperature dysregulation), otherwise not easily identifiable. The existence of a large involvement of autonomic structures both at central and peripheral levels underlines the concept of Parkinson's disease being part of a wide spectrum of degenerative disorders where multiple nervous structures are at risk.