Abstract: A case of acute hepatitis A associated with fibrin-ring granulomas in the liver is presented. Because a relationship between acute hepatitis A infection and granuloma formation had not previously been established, liver specimens were examined from both the hepatitic and recovery phases. Numerous fibrin-ring granulomas were observed in the parenchyma during the hepatitic phase. The cellular components of the granulomas were largely macrophages and CD4-positive T-cells. Granulomas had disappeared completely by the recovery phase. These results suggest that fibrin-ring granulomas were caused by hepatitis A virus infection. This virus may activate macrophages and CD4-positive T-cells through an as-yet undetermined mechanism.