UNLABELLED: The diagnosis of autoimmune hepatitis is mainly based on the finding of characteristic autoantibodies. Untreated patients have a poor prognosis because of rapid development of cirrhosis. Immunosuppressive treatment most often leads to remission. We report on 2 female patients aged 44 and 53 with autoimmune hepatitis. Initially no significant titers of autoantibodies against nuclear, cytosolic or microsomal components of the hepatocyte could be demonstrated. Seropositivity for autoantibodies was demonstrated 6 and 8 weeks later in the course. Immunosuppressive therapy with steroids resulted in rapid decrease of transaminases with persistent remission of autoimmune hepatitis. CONCLUSION: seropositivity for characteristic autoantibodies is not an absolute criterion for the diagnosis of autoimmune hepatitis. Patients with hepatitis of unknown origin should therefore be given a steroid treatment trial.