Parkinson disease is second most common Neurological Disorders. Pub-Med query for ―Parkinson disease‖ yields more than 2,000 articles per year each of the last 5 years. The cause is unknown, but growing evidence suggests that it may be due to a combination of environmental and genetic factors. Treatment during the early stage of Parkinson’s disease has evolved, and evidence suggests that dopamine agonist mono-therapy may prevent the response fluctuations that are associated with disease progression. Surgical treatment is an option for a defined patient population. The aim of this study is to provide current update about this disease. In this review we discuss recent discoveries in the fields of current understanding as epidemiology, path-physiology, diagnosis and treatment of PD and focus on how a better understanding of disease mechanisms gained through the study that provided novel therapeutic targets.