In twenty years, significant progress was made in the knowledge of viral hepatitis. Alphabet of hepatotropic viruses has extended, and C, D, E and G viruses have been added to hepatitis A and B viruses; their genomes have been characterized, allowing defining various types, subtypes and isolates with different pathological and therapeutic implications. Our knowledge regarding the epidemiology, virology and treatment of viral hepatitis is in constant evolution, allowing a better diagnostic and therapeutic approach of patients with acute and chronic hepatitis. Markers of infection and early viral kinetics provide important prognostic and therapeutic information to determine the best moment for the treatment of acute and chronic B (HB V) or C (HCV) viral hepatitis. Finally, the improved definition of risk factors for fibrosis progression to cirrhosis in chronic hepatitis may lead to preventive therapies (alcohol withdrawal, treatment of immune deficiencies) and early antiviral treatments. Progresses in liver transplantation and in the treatment of viral recurrence post-transplantation, improved prognosis of cirrhosis and small hepatocellular carcinomas. For HBV and HCV around half of french infected patients are aware of their infection (seroprevalence of 0.65 % and 0.84 % of the adult population respectively) ; access to care is easy and completly covered by the social security. Second generation-nucleos(t)idic analogues allow HBV viral suppression in all the adherent patients but have to be maintai- nedfor the whole life, by contrast with interferon which a 48 weeks course achieve sustained viral virosuppression in one third of patients, including 10 % of HBs Ag loss. HCV infection may be cured by the combination of oral direct acting antivirals in more than 95 %: hepatic and extra-hepatic manifestations are mainly reversible when a sustained virologic response corresponding to a viral cure is achieved.