We describe a novel model of status epilepticus produced by the focal application of bicuculline methiodide into the deep prepiriform cortex of rats pretreated with lithium chloride. Three out of eight rats pretreated with one dose of lithium (3 mmol/kg) 24 h prior to induction of seizures by focal bicuculline, and eight out of 12 rats pretreated with two doses of lithium (at 24 and 48 h) prior to seizure induction, exhibited continual uninterrupted convulsive seizure activity (status epilepticus) lasting between 10 min and > 2 h. This status epilepticus which was manifest both behaviorally and electroencephalographically, was sensitive to reversal by diazepam (5 mg/kg i.p.) given as long as 2 h after the onset of sustained status epilepticus. Pilocarpine (25 mg/kg) pretreatment also predisposed to status epilepticus in response to the focal application of bicuculline, but diazepam (5 or 10 mg/kg i.p.) was ineffective in suppressing the status epilepticus in the presence of pilocarpine.