The age-specific anti-hepatitis A virus (HAV) seroprevalence rates in South Korea have changed markedly since the last 2030 years with an improvement in the socio-economic, housing, and environmental-sanitation conditions. These changes are characterized by very low anti-HAV seropositive rates among individuals less than 30 years of age; however, nowadays, most adolescents and young adults at an increased risk of developing symptomatic HAV infections. The Korea Center for Disease Control Sentinel Surveillance System has recently revealed an increase in the incidence of hepatitis A infection since 2001 and has revealed a potential endemic nature of the hepatitis A infection. Hepatitis A vaccines that were introduced in 1997 in Korea have made the current anti-HAV IgG positive rates in children (less than 10 years of age) approximately 50% of the rates observed in Seoul in 2006. However, in the same year, a few children were diagnosed as having anti-HAV IgG antibodies in Busan. This suggests the presence of some difference in the vaccination policy among doctors practicing in Seoul and Busan. Thus, the current recommendation of vaccinating 12-year-old child with HAV vaccination should be emphasized and a new strategy should be developed for the vaccination program to cater to the adolescents and young adults who are not immune, as well as for persons who are at a high risk for hepatitis A viral infection such as military personnel and hospital and day care center employees. Further, urgent hepatitis A vaccinations are also needed in patients with chronic liver diseases.