Parkinson’s Disease and Nonmotor Dysfunction fills a major gap in the current rapidly growing body of knowledge concerning Parkinson’s disease. Drs. Pfeiffer and Bodis-Wollner have correctly perceived that many nonmotor features of Parkinson’s disease are given insufficient attention in the medical literature. Unfortunately, they are often also given insufficient attention by the practicing neurologists who see these patients. As recently pointed out, there is clearly much more to Parkinson’s disease than depletion of the nigrostriatal dopamine system (1). Parkinson’s disease (not just m- tiple system atrophy) is a multisystem disorder, both pathologically and in its clinical manifestations. This is clearly true for the various motor system abnormalities, which are not fully corrected by dopamine replacement therapy strategies, but also for the nonmotor system abnormalities that are the subject of this volume. Although recently there has been increased awareness of the cognitive, psychiatric, and sleep disorders commonly associated with Parkinson’s disease, many of their manifestations remain under-recognized and their importance in managing patients is underestimated. Even less attention is paid to the myriad of other nonmotor disturbances that plague these patients. For example, among the autonomic disorders, although orthostatic hypotension is well recognized, it is usually attributed to dopaminergic medications rather than to effects of the underlying disease. Urologic disorders are also very familiar in these patients, but may not be properly understood or well managed.