A case of autoimmune chronic active hepatitis with unusual extrahepatic manifestations is described. The patient exhibited marked thrombocytopenia and platelet aggregation dysfunction and morphological changes suggesting an acquired Bernard Soulier-type syndrome. This has not previously been described in association with chronic active hepatitis. The patient also demonstrated significant titres of anti-cardiolipin antibodies. This is also a new finding in association with both the liver and platelet diseases. The platelet aggregation deficit was transferable in the patient's serum rather than being intrinsic to the platelets. The three previously reported cases of acquired Bernard Soulier are reviewed and possible mechanisms for the platelet dysfunction are discussed.