There is a widespread view among psychiatrists that dissociative experiences such as depersonalisation, derealisation, absorption, and psychogenic amnesia have a traumatic etiology. This view is subjected to a critical evaluation. We also discuss an alternative interpretation namely that dissociative experiences are caused by a labile sleep-wake rhythm. We evaluated this alternative view in two exploratory studies. In study 1 we looked at the relationship between the Dissociative Experience Scale (des) and the Iowa Sleep Experiences Survey (ises) and in study 2, we checked this relationship when the response bias was controlled for. Dissociative experiences (measured with the des) correlated with the ises. The correlation between des and ises remained completely intact even when we controlled for response bias. Our findings show that dissociative symptoms are associated with typical sleep experiences such as nightmares and strange dreams. The association is not the by-product of the positive response bias which generally characterises persons with dissociative symptoms.