Electrographic aspects of convulsive and non-convulsive status epilepticus observed in 11 patients with Lennox-Gastaut syndrome were studied. All conceivable forms of EEG findings appeared during status partly due to the great variability of clinical forms. Paradoxical findings were the lack of epileptic recruiting rhythm or desynchronization during tonic status epilepticus and the lack of rapid activity frequently observed during epileptic drop attacks. Atypical findings include persistence of focal abnormalities or assymmetrical critic discharges. The various forms of chronic absence status occured in our patients according to the descriptions of Lugaresi et al. The paradoxical benzodiazepine action observed of Tassinari et al occured in one patient although restricted to the EEG record.