Autoimmune encephalitis is characterized by formation of antibodies against cell surface proteins. Antibodies against the gamma-aminobuturic acidB (GABAB) receptor lead to limbic encephalitis, drug-resistant seizures, confusion, cognitive impairment and changed behaviour. Some patients present with status epilepticus. GABAB encephalitis is associated with small-cell lung cancer or neuroendocrine lung tumour. This is a case report of a patient having status epilepticus due to GABAB encephalitis. In cases which are presumed to be autoimmune it is important that treatment starts immediately instead of awaiting antibody confirmation.