Alpha-interferon is effective therapy for patients with chronic hepatitis B and hepatitis C. Only 20% to 40% of patients, however, have sustained benefit from therapy. For the majority of patients with these diseases, alternative forms of therapy are needed. Nucleoside analogues appear to be extremely promising for the treatment of chronic hepatitis B and undoubtedly will play a major role in the management of this disease in the future. For chronic hepatitis C, prolonged therapy with interferon, improved patient selection, and combined therapy with multiple agents, such as ribavirin, may lead to an improved therapeutic response.