The present study, conducted between January 1975 and June 1983, includes 282 adult patients admitted for status epilepticus (SE) in 2 intensive care units (3.5% of all admissions). In their great majority, i.e., 201, patients had no previous history of epilepsy, and initiated the SE during the course of recent affections such as brain or systemic diseases. In 81 patients with previous seizure, epilepsy was idiopathic in 20, and symptomatic in 61, the 3 main causes being cranial traumatism, cerebrovascular accident and chronic alcoholism. SE was of various causes. The most frequent were cerebro-vascular disease, post-anoxic encephalopathy, intoxication, bacterial or viral meningo-encephalitis. In some patients, SE was preceded by manifestations such as convulsions, behavorial disturbances or conscience impairment. One should be aware of these facts and undertake or increase an anticonvulsivant medication at their onset. Duration of SE, when clearly established, was highly variable but had no apparent correlation to sequelae or death occurrences. SE itself was directly related to death in only 2 cases; in all other instances death was the consequence of the primary disease. These results are consistent with previous reports: presently SE occurs more frequently in the course of other affections than in prior epileptic patients. The better vital prognosis of SE is due to the simultaneous conjunction of new anticonvulsivant medication and supportive care associated with the cure of the causative disease.