Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an autoimmune, neuroinflammatory process that is caused by antibodies against the NMDAreceptor 2A subunit in the central nervous system (CNS). While this is an aquired disease (either post-infectious or paraneoplastic), there may be a component of genetic vulnerability. Since the first paediatric case report in 2009, it has become the second most common cause of autoimmune encephalitis in children. Patients present with psychosis, neurologic deficits and seizures. There can be a progressive decline to decreased responsiveness, catatonia and paroxysmal sympathetic hyperactivity (PSH). Autonomic instability is a hallmark of the disease. Most children recover completely, but a small percentage are left disabled or die from cardiac arrhythmia. These patients almost always require anaesthesia during diagnostic workup and occasionally for therapeutic measures, such as excision of teratoma. The NMDA-receptor is also a common target for anaesthetic agents.