Recent advances in epidemiology, virology, of clinical of hepatitis are presented in the paper. The authors pointed out that hepatitis A never becomes chronic. On the other hand, with hepatitis B or B and D, evolution to chronicity is possible. Two distinct forms of non-A non-B hepatitis are now distinguished: parenterally transmitted non-A non-B hepatitis, mainly due to hepatitis C virus; enterically transmitted non-A non-B hepatitis mainly due to hepatitis E virus. C virus hepatitis is characterized by a frequent course to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Chronic forms are associated with the presence of anti-HC antibodies in the serum. These antibodies are rarely present in the acute stage of the disease. Hepatitis E is almost exclusively encountered in developing countries. Like with A virus hepatitis, chronicity never occurs. However, fulminant hepatitis is possible in pregnant women in the third trimester of pregnancy. There is no routine serological test. Development of vaccines against A, E and C viruses can be expected very soon. There is no specific treatment of acute viral hepatitis.