A 32-year-old female with depression on treatment, was presented with acute psychosis, behavioural symptoms, autonomic instability and a prodromal illness. This occurred on a background of a strong family history of schizophrenia. Despite escalating doses of anti-psychotics, she failed to improve. Her CSF showed a lymphocytic pleocytosis and confirmed the presence of anti-NMDAR antibodies. Following treatment with immunotherapy and excision of her underlying ovarian tumour, she showed a dramatic and seemingly full recovery of her psychotic symptoms. She was weaned off all medications with no residual symptoms. Clinician awareness is important to treat this uncommon but potentially reversible condition.