Schizophrenia patients or their relatives have been reported to have either higher or lower than expected prevalence of some autoimmune disorders, including rheumatoid arthritis, ankylosing spondylitis, type 1 diabetes, thyroid disorders and celiac disease. The purpose of the case report was to estimate the association of schizophrenia with ankylosing spondylitis and other autoimmune diseases. A 27-year-old, single male, university graduate, unemployed; was hospitalized with mutism, nutrition denial and paranoid delusions. After psychiatric examination, laboratory tests, evaluating his psychiatric history for 4 years; catatonic schizophrenia was diagnosed as well as 9 year old with a comorbid diagnosis of ankylosing spondylitis. While we were planning to apply electroconvulsive treatment, antipsychotic treatment was received the response in 3 days. Schizophrenia is associated with a larger range of autoimmune diseases than already suspected. Our case report required that the arthropathies appear before the patient was diagnosed with schizophrenia, which may have inşuenced this result, since many cases of arthropathies have onset much later than the age at onset for schizophrenia as with another researches. Future research on comorbidity has the potential to advance understanding of pathogenesis of both psychiatric and autoimmune disorders.