Immune-mediated liver diseases contribute significantly to morbidity and mortality due to liver failure and the need for liver transplantation. The pathogenesis of the immune-mediated chronic liver diseases, primary sclerosing cholangitis, autoimmune hepatitis, and primary biliary cirrhosis, is poorly understood. Genetic susceptibility factors may play a role, but increasing attention is being given to the association between environmental factors and these diseases. The existence of such a relationship is supported by epidemiologic surveys, animal models, and geographic clustering analyses. Unearthing the cause of this association may provide insight into the pathogenesis of immune-mediated chronic liver diseases and autoimmunity.