Although several RBD screening questionnaires have been developed, diagnosis can only be definitely confirmed on the basis of polysomnography. New methods for scoring electromyography (EMG) activity during REM sleep have been proposed during recent years and cutoff values have been established. The latest cutoff values for scoring EMG activity during REM sleep are included in the International Classification of Sleep Disorders (ICSD). The cutoff of 27 % muscle activity during REM sleep suggested by the Sleep Innsbruck Barcelona (SINBAR) group was also included in the third edition of the ICSD. The best-researched treatments for RBD are clonazepam and melatonin.