Recent developments make it possible to identify the causative virus in most cases of acute and chronic viral hepatitis. Improvements in supportive care and the availability of hepatic transplantation have considerably reduced mortality for the fulminant forms of acute viral hepatitis, and advances in antiviral therapy have led to the possibility of cure for some patients with chronic viral hepatitis and improvement for many others. Algorithms are presented as a guide to the diagnosis and management of acute and chronic viral hepatitis.