Many patients with Parkinson's disease (PD) complain about sleep disturbances. These symptoms originate from motor symptoms, nocturnal problems, psychiatric symptoms, and other sleep disorders including Excessive daytime sleepiness (EDS), REM sleep behavior disorder (RBD), Restless legs syndrome (RLS), and Sleep apnea syndrome (SAS). Especially, RBD is paid attention to prodromal symptoms of PD. Also, one third of patients with PD have RBD symptoms. Moreover, RBD is one of aggravating factors of motor symptoms, autonomic dysfunctions, and dementia. Now, the evidence based medicine for sleep disturbances is lack in patients with PD. We need to evaluate various causes of sleep disturbances in detail and deal with individuals.