Anti-NMDAR encephalitis is a rare autoimmune disorder associated with antibodies against the NMDA receptor, primarily affecting children and young adults. It presents with a multistage illness, starting with psychiatric symptoms, memory deficits, seizures, and language disintegration, progressing to unresponsiveness with catatonic features and autonomic instability. The disorder is more common in women over 18, especially black women, and is often associated with ovarian teratomas. Patients with a tumour respond better to treatment and require less second-line immunotherapy than those without a tumour. Over 75% of patients recover, with recovery occurring in reverse order of symptom onset and associated with a decline in antibody titres. The antibodies cause a reversible decrease in synaptic NMDARs through crosslinking and internalisation. The disorder is distinct from other autoimmune encephalitides and is linked to NMDAR dysfunction. It is more frequent than other paraneoplastic encephalitides. Diagnosis involves brain MRI, EEG, and CSF analysis, with antibodies detected in both serum and CSF. Treatment includes immunotherapy, tumour resection, and, in some cases, second-line therapies. Recovery is a multistage process, often delayed by months. The disorder can occur during pregnancy and has a mortality rate of about 4%. It is important to differentiate from other conditions like viral encephalitis and neuroleptic malignant syndrome. The pathogenic mechanism involves immune-mediated NMDAR dysfunction, and the disorder is linked to NMDAR hypofunction in schizophrenia. Future studies should focus on understanding the immune response in the CNS and improving treatment strategies.Anti-NMDAR encephalitis is a rare autoimmune disorder associated with antibodies against the NMDA receptor, primarily affecting children and young adults. It presents with a multistage illness, starting with psychiatric symptoms, memory deficits, seizures, and language disintegration, progressing to unresponsiveness with catatonic features and autonomic instability. The disorder is more common in women over 18, especially black women, and is often associated with ovarian teratomas. Patients with a tumour respond better to treatment and require less second-line immunotherapy than those without a tumour. Over 75% of patients recover, with recovery occurring in reverse order of symptom onset and associated with a decline in antibody titres. The antibodies cause a reversible decrease in synaptic NMDARs through crosslinking and internalisation. The disorder is distinct from other autoimmune encephalitides and is linked to NMDAR dysfunction. It is more frequent than other paraneoplastic encephalitides. Diagnosis involves brain MRI, EEG, and CSF analysis, with antibodies detected in both serum and CSF. Treatment includes immunotherapy, tumour resection, and, in some cases, second-line therapies. Recovery is a multistage process, often delayed by months. The disorder can occur during pregnancy and has a mortality rate of about 4%. It is important to differentiate from other conditions like viral encephalitis and neuroleptic malignant syndrome. The pathogenic mechanism involves immune-mediated NMDAR dysfunction, and the disorder is linked to NMDAR hypofunction in schizophrenia. Future studies should focus on understanding the immune response in the CNS and improving treatment strategies.