This issue of Clinics in Geriatric Medicine, guest edited by Drs. Carlos Singer and Stephen G. Reich, is devoted to Parkinson Disease. Articles in this issue include: Parkinson Disease: An overview of epidemiology, pathology, genetics and pathophysiology; Diagnosis and Differential Diagnosis of Parkinson Disease; Tremor in the Elderly: Is it Parkinson Disease?; Management of Early Parkinson Disease; Management of Advanced Parkinson Disease; Orthostatic Hypotension in Parkinson Disease; Management of Urological and Sexual Dysfunction in Parkinson Disease; Gastrointestinal Care of the Parkinson Patient; Cognitive Impairment and Dementia in Parkinson Disease; Depression and Anxiety in Parkinson Disease; Hallucinations, Delusions, and Impulse Control Disorders in Parkinson Disease; Sleep Disorders in Parkinson Disease; Orthopedic Care of the Parkinson Patient; Driving in Parkinson Disease; Palliative Care in Parkinson Disease; Multidisciplinary Care of Parkinson Disease: Fall prevention, fatigue, exercise, rehabilitative therapies, caregiver strain; and Hospitalization of the Patient with Parkinson Disease.