Current therapies for chronic viral hepatitis, autoimmune "lupoid" chronic active hepatitis, and drug-induced chronic hepatitis are discussed in the context of recent advances in our understanding of the pathophysiology of chronic active liver disease. Accurate diagnosis is the cornerstone of proper treatment; the limitations and pitfalls of conventional techniques are discussed. Current theories of the pathogenesis of chronic hepatitis B are reviewed to provide a framework for the use of antiviral drugs. Data from the early results of therapy with adenine arabinoside, acyclovir, and immunomodulatory agents are reviewed, and the theoretical basis for the use of alpha-interferon as well as preliminary data supporting its efficacy is presented. Strategies for the treatment of chronic delta hepatitis and chronic non-A, non-B viral hepatitis are discussed as well. The immunological changes associated with autoimmune chronic active hepatitis are described to help define those patients with chronic active hepatitis who are likely to respond to immunosuppressive therapy. The recognized hazards of long-term corticosteroid therapy are indicated and guidelines for the management of these patients are suggested. Chronic drug-induced liver disease will usually improve with cessation of the offending agent. An approach to the patient with suspected drug-induced chronic hepatitis is indicated. Finally, the role of liver transplantation is mentioned as the ultimate treatment modality available for endstage liver disease.