Objective:To outline recently described movement disorders during sleep which are common and poorly recognised.Data sources:Computer‐based literature search up to July 1990 (with the index terms sleep disorders, sleep myoclonus, nocturnal myoclonus, periodic movements in sleep, REM behaviour disorder and parasomnias) supplemented by a manual search through the references of papers obtained by computer search and a manual search through contents of the following journals:Sleep, Sleep Research, NeurologyandBrain.Data synthesis and conclusion:There is a group of common and poorly recognised movement disorders during sleep. The patient usually presents complaining of disturbed sleep, daytime somnolence and abnormal nocturnal behaviour. These conditions are susceptible to precise diagnosis and effective treatment.