This chapter presents the clinical history, examination, follow-up, treatment, diagnosis, and the results of the procedures performed on a 73-year-old patient who complained of two recent violent dreams that resulted in significant injury. His past medical history included an anterior wall myocardial infarction, sinusitis and a remote history of tuberculosis. The patient was treated with clonazepam 1.0 mg every evening before sleep, with complete resolution of all violent dream-related behaviors over the following year. The MRI scan revealed a right subdural hematoma without mass effect, and a few small 2-3mm foci of deep white matter changes. The polysomnography (PSG) study revealed significant periodic limb movements. A follow-up assessment by a movement disorders specialist led to the diagnosis of Parkinson's disease. The patient's history and PSG analysis are classical for, and diagnostic of, REM-sleep behavior disorder (RBD), which is defined in ICSD-2 as a parasomnia associated with REM sleep.