Encephalitis may present with seizures or status epilepticus, and the etiology is usually presumed. Specific antibodies to ion channels, receptors, and other synaptic proteins were identified during the past decade. However, only a few studies investigated antiglutamic acid decarboxylase antibodies and antibodies to cell membrane ion channels or surface antigens in pediatric encephalitis and status epilepticus. We examined antibodies to glutamic acid decarboxylase and cell membrane ion channels or surface antigens in acute-phase serum from 17 children with encephalitis and status epilepticus. Antiglutamic acid decarboxylase antibody titers were compared with those of control children manifesting therapy-resistant epilepsy. Antiglutamic acid decarboxylase antibody titers were significantly higher in those with encephalitis and status epilepticus than in those with therapy-resistant epilepsy. No patient demonstrated antibodies to cell membrane ion channels or surface antigens. Six children exhibited positive antiglutamic acid decarboxylase antibodies. One child died, three manifested postencephalitic epilepsy with neurologic deficits, and two recovered well. Higher antiglutamic acid decarboxylase antibody titers were evident in the children with encephalitis and status epilepticus. Clinicians should be aware of the potential role of antiglutamic acid decarboxylase antibodies in children with encephalitis and status epilepticus.