Among disorders of sleep in children, pavor nocturnus ("night terrors") is common and considered harmless. Yet the clinical picture, the child's personality and the polygraphic electroencephalographic recordings suggest that it should be treated sooner and more often than is usually done. Somnambulism ("sleep walking") also is very frequent. It has no consequences in most cases, but it may be the cause of serious events such as falling out of a window which is rare but may result in death or disablement. Some children have repeated attack of somnambulism, and these constitute a true pathology of sleep requiring a specific treatment that will cure or improve. All this must be known to the practitioner who will inform the parents.