This paper gives a review on the clinical features of autonomic failure which occur in idiopathic Parkinson's disease (PD), mainly based on the recent publications, especially from Japan. In 1817, James Parkinson already mentioned bowel and bladder dysfunctions in his original article. Since then, a number of clinical studies have disclosed the occurrence of autonomic failure in this disease. It is known that relatively minor degrees of orthostatic hypotension are not rare, but other features of autonomic failure are rather uncommon, generally mild in severity and nonprogressive. Orthostatic hypotension is suggested as a possible side effect of L-dopa. Postprandial hypotension is occasionally found, and vasopressin is proven to prevent it remarkably. There is low electrocardiographic R-R interval variability which indicates impaired parasympathetic activity. Thermoregulatory sweating is nearly normal, but its center is functionally impaired. Resting skin temperature is slightly lower. Both salivation and lacrymation are quantitatively within normal limits. Little is known on sexual function in PD.