Anti-NMDA receptor encephalitis is a treatable autoimmune disease characterized by cognitive, motor and psychiatric features that primarily affects young adults and children. We present a case of a 7-year-old boy with asymmetrical (mainly right hemibody) and abnormal polymorphic movements without concomitant scalpictal EEG changes but had background slowing predominating over the left hemisphere. This report illustrates previous descriptions of asymmetric presentation of abnormal movements in pediatric anti-NMDA receptor encephalitis and emphasizes the importance of video-EEG interpreted within the overall clinical context, to differentiate epileptic from non-epileptic abnormal movements in patients with autoimmune encephalitis.