OBJECTIVE: Lennox-Gastaut syndrome (LGS) is a refractory epilepsy in children. Some are accompanied by electrical status epilepticus during sleep (ESES)rendering treatment more difficult. This study examined the short-term effect of intravenous methylprednisolone (MP) pulse therapy on LGS with ESES. METHODS: Twenty-two children with LGS, who were confirmed with ESES by electroencephalograph (EEG), received MP intravenous pulse therapy followed by prednisone administration. RESULTS: Fifteen patients had partial remission of seizures (68.2%)and the EEG showed reduced epileptiform discharges in 16 cases (72.7%). No severe adverse effects were found. CONCLUSIONS: MP pulse therapy can alleviate the symptoms and ESES in children with LGS. If anti-epileptic drug treatment is not effective, the therapy should be considered.