Autoimmune hepatitis (AIH) is an intermittently progressive liver disease characterized by hypergammaglobulinemia, autoantibodies, predominately periportal hepatitis, and a favorable response to corticosteroid therapy in most cases. There are no pathognomonic markers of autoimmune liver disease; rather, the diagnosis must be based on the presence of a constellation of characteristic clinical, laboratory, and histologic features in patients without other causes of such liver pathology. Although prednisone or prednisolone are the mainstays in initial therapy of AIH, azathioprine or other drugs with similar immunosuppressive mechanisms are of benefit for steroid-sparing effects or for use as monotherapy to maintain long-term remission. A fraction of patients meeting diagnostic criteria for AIH remains in long-term remission following withdrawal of immunosuppressive therapies, but in most patients, this disease represents a chronic condition requiring life-long monitoring and therapy.