Acquired hemophilia is a rare disorder associated with fatal bleeding caused by the development of autoantibodies against factor VIII. Here, we report the cases of two young women with acquired hemophilia who presented with massive internal hemorrhage and purpura. Both patients were successfully treated with combination therapy including factor VIII or factor VIII bypassing agent, immunosuppressants, and therapeutic plasmapheresis. (Korean J Med 77:367-370, 2009)