Rapid eye movement (REM) sleep behavior disorder (RBD) was first formally identified in 1986 by Schenck and Mahowald in five elderly subjects presenting similar motor behavioral patterns during REM sleep consisting of violent dream-enacting behaviors. The clinical manifestations of RBD are typically dream-related motor-behavioral manifestations that appear to be the enactment of a fight. Subclinical or preclinical RBD, status dissociatus and parasomnia overlap syndrome are the clinical-pathophysiological subtypes of RBD, according to ICSD-2. The literature contains anecdotal reports of co-existing RBD and narcolepsy in both adults and children, in some cases with the RBD episodes as the presenting symptoms. The parasomnia and non-parasomnia disorders are taken into account in the differential diagnosis of RBD. In humans, RBD has been associated with several etiologies and abnormalities. Anecdotal reports and uncontrolled, retrospective studies of small patient series suggest that levodopa and pramipexole (D3 agonist) reduce RBD manifestations.