Parasomnias are unwanted physical events, experiences, and autonomic nervous system activity that occur during sleep or during sleep-wake transitions. Rapid Eye Movement (REM) Sleep Behavior Disorder (RBD) is a parasomnia where the normal REM atonia is diminished or absent, with release of dream enactment behavior. RBD is more common in men, however it is not rare in women and needs to be considered in cases of sleep related injury. It is important to recognize the unique features of RBD and the relationships to neurodegenerative disorders. Finally, REM parasomnias are treatable with the proper identification and treatment of underlying co-morbid sleep disorders, the discontinuation of inducing agents, as well as the judicious use of pharmacotherapy and environmental modification.