To identify the risk factors of pneumonia in patients with Anti-N-methyl-D-aspartate (Anti-NMDA) receptor encephalitis.This is a retrospective study.Department of Neurology in West China Hospital of Sichuan University.Patients with a definitive diagnosis of anti-NMDA receptor encephalitis.Risk factors associated with pneumonia were examined by bivariate analysis and multivariate logistic regression model.A total of 104 patients were included in this study, of which 41% patients (n = 43) were diagnosed with pneumonia at 7 days (range: 4-40 days) after admission. The occurrence of pneumonia was associated with prolonged hospital stays, a higher rate of poor outcome, and extra healthcare costs. Risk factors associated with pneumonia included Glasgow coma scale score (GCS), abnormal movements and hypokalemia.Pneumonia is a common complication in anti-NMDA receptor encephalitis. In the present study, we found that disorders of consciousness, abnormal movements, and hypokalemia were independent risk factors for pneumonia in inpatients with anti-NMDA receptor encephalitis. Pneumonia prolongs the patients' hospital stay, hospitalization expenditures, and affects the patients' prognosis.