The presence of autoantibodies against factor VIII is an unusual but serious complication in rheumatoid arthritis. We describe the case of a patient who developed this kind of complication, with spontaneous bleeding and marked changes in the haematological parameters, that was unsuccessfully treated with a high dose of intravenous gammaglobulin. Subsequently, combined therapy with porcine factor VIII concentrate, cyclophosphamide and steroids led to the disappearance of the anti-factor VIII autoantibodies.