A retrospective case note study of the aetiology and course of children in convulsive status epilepticus (CSE) admitted to a large paediatric intensive care unit (PICU) was undertaken between January 1999 and April 2004. Status epilepticus was defined as a prolonged (>30 min) tonic-clonic seizure irrespective of whether the seizure had stopped prior to admission to PICU. During this period, 137 (74 male) children aged 1 month to 15 years were admitted to PICU with 147 episodes of status epilepticus. Forty-seven of the 137 children (34%) were admitted following a prolonged febrile seizure. Thirty-eight of the 137 children (28%) had a remote symptomatic cause for the CSE, 24 (18%) were admitted for an acute symptomatic cause and 15 (11%) were admitted with an acute exacerbation of a pre-existing idiopathic/cryptogenic epilepsy. Six children had a progressive encephalopathy and no cause was identified in the remaining 7 of the 137 children (5%). Forty-nine (36%) of the 137 children had pre-existing epilepsy. The mean duration of CSE was 44 min. Forty-nine (36%) children admitted to PICU who had received a benzodiazepine with either phenobarbital or phenytoin, required further treatment to terminate the presenting episode of CSE. Forty-two of these 49 were treated with thiopentone anaesthesia and the remaining 7 with a continuous infusion of midazolam, successfully terminating status in all. No child died. Of the 70 children considered to be previously neurologically and developmentally normal prior to admission, only 1 child demonstrated a new gross neurological abnormality at the time of latest follow-up. Seven patients (5%) developed new or de novo epilepsy.