A 57-year-old woman affected with Sjögren's syndrome without bleeding history developed spontaneous hematomas at the arms, the left foot and the thigh, cutaneous hemorrhages and hematuria. Routine coagulation tests showed a prolongation of activated partial thromboplastin time associated with a marked reduction of factor VIII activity (VIII: C 5%). Other deficiencies of blood coagulation factors, especially von Willebrand factor, were excluded. Measurement of factor VIII inhibitor revealed an activity of 26.4 Bethesda units/ml. These findings were consistent with the diagnosis of acquired hemophilia A due to the presence of a factor VIII inhibitor. The patient was treated with a combination of prednisone and azathioprine. The therapy led, in a few months, to a significant reduction of factor VIII: C inhibitor and she did not require replacement therapy. Furthermore, there was a complete remission of the bleeding tendency. Long-term therapy for about 3 years induced the complete disappearance of the inhibitor and a full normalization of coagulation tests.