Hepatitis A (HA) presents a benign evolution, but occasionally some patients develop a more severe disease. Previously to 2005 hepatitis A was an important cause of acute liver failure (ALF) and hepatic transplant. In 2003, a consensus in the Argentinian Pediatrics Society was done; it had just recommended the inclusion of the vaccine in the mandatory immunisation schedule. This was issued by the Health Ministery, and was applied on June 1st, 2005. The schedule was one dose at the age of one year of age. Since then, an important reduction of HA was registered, without any case of ALF since 2006. Follow-up studies so far showed low viral circulation and persistence of antibodies to 5 years later.