Background: Barbiturate poisoning is rare but potentially fatal. Case Report: We reported a case of barbiturate poisoning in a 28-year-old woman who recovered from lethal pentobarbital deliberate self-poisoning. The initial blood pentobarbital concentration was 61 mg/L, corresponding to a potentially lethal dose. Despite the ingestion of a high dose of pentobarbital, the electroencephalogram revealed an unattended pattern compatible with possible nonconvulsive status epilepticus. Following resuscitation maneuvers, appropriate care, and antiseizure medication, the patient awakened after 7 days. The evolution was excellent without neurological deficits at 2 months.Conclusion: Despite the expected and known effects of high-dose pentobarbital in reducing and suppressing cortical activity in the brain, the present case demonstrates that lethal dose of pentobarbital may have an epileptogenic effect. Our hypothesis was that the mechanism of the origin of such a picture is a relatively abrupt decrease in toxic doses of pentobarbital, resulting in a withdrawal phenomenon.