Eighty-two episodes of status epilepticus or clusters of seizures in 45 children were treated with intravenous midazolam. Twenty-two children had epilepsy and 23 had acute symptomatic seizures. Midazolam was administered as an intravenous bolus dose at 0.06-0.4 mg/kg (mean 0.173 mg/kg), followed by continuous intravenous infusion at 0.05-0.4 mg/kg/hr (mean 0.191 mg/kg/hr). The mean duration of the treatment was 132.7 hours. Complete arrest of seizures was achieved in 62 episodes, and decrease by more than 50% in seizure frequency in 8 clusters of seizures. In these 70 successfully treated cases (85.4%), the effect appeared within 45 minutes after the initiation of therapy. No severe adverse effects were noted except stridor and mild respiratory suppression in 2 cases. Midazolam is an effective and safe drug to be used in a first-line or second-line therapy for status epilepticus and clusters of seizures in children.