Autoimmune hepatitis is a chronic necroinflammatory disease of unknown etiology that is characterized by increased aminotransferases, serum autoantibodies, increased immunoglobulin G levels, and histological interface hepatitis. The disease does not have a pathognomonic clinical, laboratory, or histological feature; diagnosis depends on a combination of clinical and pathologic criteria which also form the basis for a weighted scoring system to aid diagnosis. Liver biopsy is an essential part of the diagnostic criteria and is also crucial to the management of the disease. This review focuses on the diagnosis, microscopic features, differential diagnosis and overlap syndromes of autoimmune hepatitis.