This is a case of a young woman who developed neurological and psychiatric symptoms 3 days after resection of an immature teratoma. She was diagnosed with anti-NMDA receptor encephalitis via positive serum antibody titres, which was later confirmed with cerebrospinal fluid antibody titres. Given her cancer diagnosis, she underwent treatment with bleomycin, etoposide and cisplatin chemotherapy in addition to 5 days of high-dose steroids (1 g of intravenous methylprednisolone) for the encephalitis. This treatment regimen led to significant clinical improvement 3 weeks after completion of one cycle of chemotherapy.