Purpose: To discuss and propose a definition of autonomic status epilepticus (SE), describe its clinical and EEG features, and review what is known about its epidemiology, pathophysiology, differential diagnosis, and management. Methods: An international consortium of established researchers in the field was identified from their published work, agreed the purpose of the project, searched the literature, and, by use of e-mail communication, agreed the consensus document. Results: Autonomic SE is a condition lasting at least 30 min and characterized by epileptic activity causing altered autonomic function of any type at seizure onset or in which manifestations consistent with altered autonomic function are prominent (quantitatively dominant or clinically important) even if not present at seizure onset. It is best described, and probably most commonly encountered in children, with Panayiotopoulos syndrome. However, it also occurs in children with symptomatic epilepsies and, exceptionally, in adults. Its pathogenesis and most appropriate management are poorly understood Conclusions: It is hoped that this document will help clinical recognition of Autonomic SE, reduce misdiagnosis, and promote further interest and studies into what has been a relatively neglected area.