Hepatitis A is a disease that has a close relationship with the level of public health and sanitation in a society. The incidences of hepatitis A in the Republic of Korea have decreased due to improvements of public health and sanitation over the past few decades. However, the number of hepatitis A patients among adolescents and adults has recently increased, while the number of antibody carriers has decreased despite the introduction of vaccination for hepatitis A in the Republic of Korea. Hepatitis A is mainly transmitted through contact with an infected person or the eating of raw fish and shellfish. In addition, it can be transmitted through a blood transfusion involving infected blood. In the Republic of Korea, several safeguards at the national level operate to prevent transfusion-related infections and to ensure the safety of the blood donors and the recipients. This study tries to examine the cases of transfusion-transmitted infections of hepatitis A in the Republic of Korea.