Parkinson’s disease (PD) is a chronic, progressive movement disorder that affects the lives of at least one half million patients across the United States. The average onset of characteristic motor symptoms, which are initially subtle and impact purposeful movement, occurs in the sixth decade. People with PD also experience significant non-motor symptoms including changes in cognition and mood, sleep disturbances, and autonomic dysfunction. Currently available pharmacological and surgical treatments provide relief from some motor symptoms, but do not halt the ultimate progression of the disease. Although significant research advances have been made, including the recent identification of possible environmental and genetic risk factors for PD, further research is required to elucidate underlying causes of PD and to discover improved treatments.