A case of primary biliary cirrhosis with stage III histological changes associated with an asymptomatic thrombocytopenic purpura with raised antiplatelet antibody levels is described. This new association of two conditions in which an autoimmune participation is generally accepted suggests a predisposition to this form of disease and/or the intervention of common trigger factors; however, an analysis of known etiological mechanisms does not exclude the possibility of a fortuitous association.