Background: Autoimmune hepatitis (AIH) is a disease of unknown etiology characterised by interface hepatitis, hypergammaglobulinemia, circulating autoantibodies and a favourable response to immunosuppression [3,8]. Left untreated, patients with autoimmune hepatitis have an unfavourable outcome. Case report: Describe a case of hepatic encephalopathy, Child C cirrhosis due to autoimmune hepatitis at Cho Ray hospital. A 47 year-old female has symptoms of arthritis, hepatitis for one year. She has admitted to hospital some times with diagnosis of acute hepatitis of an unknown etiology. On physical examination, the patient had jaundice and mental disorder. The laboratory tests showed: serum aminotransferase and bilirubin levels much increased, platelet count and albumin level decreased (60 GIL, 2.9g/dL respectively). The patient also has coagulopathy (prolongation of INR). ANA test was positive. Abdominal ultrasound and fibroscan revealed various pathological patterns such as chronic hepatitis, cirrhosis. Liver biopsy showed that it was interface hepatitis. The patient received prednisone and support-ive treatment. She returned to the hospital for laboratory assessment of biochemical and hematologic values. At the end of 14 months, the disease was stabilized, every biochemical and hematologic value was good. The cirrhosis has regressed. Conclusion: The patient with hepatic encephalopathy, Child C cirrhosis due to autoimmune hepatitis was successfully treated in Cho Ray hospital.