Falls and postural instability are common complications of advanced Parkinson's Disease (PD). Falls in PD often have devastating consequences, leading to a poor overall prognosis. In addition, falls in PD are associated with substantial medical expenses due to treatment of injuries and nursing home admission. The risk of falls in older PD patients is aggravated by "generic" age-related factors, such as sedative medication or poor vision. Observations on elderly persons without PD suggest that a multifactorial prevention program might be more effective. We propose to investigate the effectiveness of a multifactorial prevention program aimed at the prevention of falls in PD, which is based on disease-specific treatment strategies with demonstrated efficacy in PD, as well as prevention strategies with proven effectiveness for the general elderly population.