Introduction In schizophrenia, patients can experience delusions or hallucinations regarding their food or health status, leading to diminished intake. Fasting or not eating a balanced diet can cause neurological complications after severe vitamin B1 malnourishment. The precise signs and symptoms of Wernicke's Encephalopathy (WE) in schizophrenia are not clear. Our aim, therefore, was to conduct a systematic review of the characteristics of WE in patients with schizophrenia. Methods We conducted our search from inception using Mesh terms schizophrenia, Wernicke Encephalopathy, Korsakoff's syndrome. We searched Pubmed, ISI Web of Science, and Scopus. We defined WE as mental, oculomotor, and motoric alterations and thiamine deficiency; schizophrenia was defined as psychosis, hallucinations and/or delusions; adequate WE treatment as >500 mg/day intramuscular or intravenous. Our search yielded 15 WE cases. Results WE is characterised by a triad of mental status change, ocular signs and ataxia. In alcohol use disorder, this triad is present in 16% of the cases, but 12 out of the 15 published schizophrenia cases presented themselves with a full triad. Importantly, as an additional characteristic, patients often lost weight within a short period of time. Conclusions The development of a full triad and additional symptomatology suggests a late recognition of signs and symptoms of WE in schizophrenia. Prophylactic thiamine checks and treatment in patients with schizophrenia are relevant, and if WE is suspected adequate parenteral thiamine supplementation is necessary.