Abstract：Anti-N-methyl-D-aspartate (NMDA)-receptor encephalitis is a paraneoplastic encephalitide that causes various symptoms. It occurs especially in young women, with about 60% of cases being associated with ovarian teratoma.We report two cases of emergency laparoscopic surgeries for anti-NMDA-receptor encephalitis associated with ovarian teratoma.Case 1: A 17-year-old woman had headache, fever and vomiting. A week later, she also had abnormal behavior and hallucination and entered hospital. CT scan detected left ovarian teratoma. As anti-NMDA-receptor encephalitis was suspected, she underwent laparoscopic left ovarian cystectomy. She needed post-operative respirator management for 2.5 months. Although discharged after 4.5 months, she was sent to a psychiatrist after 7 months because of domestic violence. The pathological diagnosis was an immature teratoma, but there is no sign of recurrence.Case 2: A 26-year-old woman had fever, headache and fatigue. A few days later, she also had memory disorder and entered hospital. CT scan detected right ovarian teratoma. As anti-NMDA-receptor encephalitis was suspected, she underwent single incision laparoscopic right salpingo-oophorectomy. She needed post-operative respirator management for 9 months and left hospital after 1 year. The pathological diagnosis was a mature teratoma.Antibodies against NMDA-receptor were positive in both cerebrospinal fluids.Early diagnosis and surgery are important for quick recovery of anti-NMDA-receptor encephalitis associated with ovarian teratoma. Even so, patients don't necessarily recover quickly without aftereffects. We should review operative methods, because the patient is young and cannot agree and immature teratoma prevalence is high. Whether a tumor is benign or malignant, it is important to prevent leakage of tumor contents whenever possible.