Symptoms of cholestasis, including epigastralgia, fever, and jaundice, with marked increases in peripheral eosinophils and serum IgE in a 20-year-old man are reported here. Endoscopic retrograde cholangio-pancreatography (ERCP) detected constrictions of the bile ducts, compatible with primary sclerosing cholangitis (PSC). The symptoms and blood parameters of liver dysfunction were associated with the degree of eosinophilia and high serum IgE levels. During corticosteroid therapy, all of these parameters improved, and morphologic improvements of the bile ducts were also observed. The pathogenesis of PSC may be explained, in part, by the concept of hypereosinophilic syndrome or allergic reaction.