The performance of anti-NMDAR Encephalitis One-Year Functional Status (NEOS) in predicting the 1-year functional status in Chinese patients with anti-NMDAR encephalitis is unknown. We recruited patients with anti-NMDAR encephalitis from the Multicenter and Prospective Clinical Registry Study of Anti-NMDAR Encephalitis in Beijing Area. Patients were followed up for 1 year. We defined the poor functional status as a modified Rankin Scale score of more than 2 and good functional status as a modified Rankin Scale score of no more than 2. We performed a receiver-operator characteristic analysis to assess the discriminatory power of the NEOS score in predicting the 1-year functional status by using the area under the curve (AUC). Calibration was assessed by Pearson correlation coefficient and Hosmer-Lemeshow tests. Among the 111 patients with anti-NMDAR encephalitis recruited from 364 potentially eligible participants, 87 (78.4%) had good functional status at 1 year, whereas the remaining 24 (21.6%) had poor functional status. The AUC of the NEOS score for 1-year poor functional status was 0.86 (95% CI 0.78-0.93, p < 0.001). The increased NEOS was associated with higher risk of 1-year poor functional status in patients with anti-NMDAR encephalitis. The NEOS score is considered a reliable predictor of the risk of 1-year poor functional status in Chinese patients with anti-NMDAR encephalitis. This score could help to estimate the velocity of clinical improvement in advance. NCT02443350. This study provides Class III evidence that in patients with anti-NMDAR encephalitis, the NEOS score predicts 1-year functional status. Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.