PURPOSE: Recently, the incidence of acute hepatitis A has increased nationwide and is related to a low rate of IgG anti-HAV production. To establish effective measures for preventing hepatitis A virus infection, an epidemiologic study on the seroprevalence of anti-HAV is needed. Thus, we investigated the seroprevalence of IgG anti-HAV in children living in Gwangju and Jeonnam. METHODS: IgG anti-HAV levels were measured in a total of 1,435 patients who visited Chosun University Hospital between January 2009 and December 2009. RESULTS: The overall seropositve rate was 40.8% (586/1,435). The seropositive rates were 41% among children under the age of 1 year, 49.9% for children 1~5 years old, 51.1% among individuals 5~10 years old, 12.9% for individuals 10~15 years old, and 8.2% for subjects over 15 years old. There was no significant difference between genders in any group. The seropositive rates in Gwangju and Jeonnam were 57.3% and 32.9% for children under the age of 1 year, 52.5% and 44.3% for children 1~5 years old, 60.2% and 33.9% among children 5~10 years old, 14.1% and 9.7% for children 10~15 years old, and 10.8% and 4.2% for individuals over 15 years old. CONCLUSION: The results demonstrated the low rates of IgG anti-HAV, particularly among subjects over 10 years old, which suggests the possibility of increasing clinical HAV infection rates among adults in the near future. We should actively prevent the spread of hepatitis A virus. Vaccination is the most effective means of preventing hepatitis A virus transmission among persons at risk for infection. Hepatitis A vaccination is recommended for children who have low IgG anti-HAV seropositive rates.