Parkinson's disease (PD) is the second most common neurodegenerative disease in the USA. Although PD is traditionally recognized by its motor symptoms, refinement of our clinical and pathological tools has led to increasing recognition that PD also causes significant nonmotor deficits. Three main treatment strategies are currently used to provide motor symptom relief in patients with early PD. These strategies include using dopamine agonists as monotherapy, long lasting dopamine therapy, and nondopaminergic agents. The mortality rate of PD is about three times higher than the mortality rate in the normal age-matched population before the introduction of l-dopa treatment. To accelerate the development of novel PD therapies, it is essential to identify reliable biomarkers for PD. Lastly, equipped with new understanding of the molecular basis of PD, efforts are now targeted toward overcoming the major obstacles to developing an effective neuroprotective therapy for PD, including accurate animal models of PD.