Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis, the most common type of autoimmune encephalitis, is characterized by autoantibodies against NMDA receptor. Patients with anti-NMDAR encephalitis also present with various non-specific symptoms, such as flu-like symptoms, neurological, and psychiatric manifestations. Here, we first reported a rare case of anti-NMDAR encephalitis in a 36-year-old male alcohol abuser. The patient presented with acute psychiatric symptoms with no abnormality in neuroimage examination and laboratory test results. Alcoholism was proposed as the most likely diagnosis. However, stopping alcohol drinking and symptomatic treatment were not effective, and 12 days later, the disease progressed with seizures and unconsciousness. Routine analysis of the cerebrospinal fluid (CSF) showed no abnormality. Importantly, anti-NMDA receptor antibodies were detected in his CSF, indicating that the patient has anti-NMDA receptor encephalitis. Consistently, γ-immunoglobulin therapy dramatically improved symptoms, which further confirmed the diagnosis. As anti-NMDAR encephalitis has no unique clinical characteristic and its psychiatric manifestations may overlap with the alcoholism-associated psychiatric symptoms, precaution should be taken to differentiate anti-NMDAR encephalitis from alcoholism in alcohol abusers.