In the last three decades, hemophilia has moved from the status of a neglected and often fatal hereditary disorder to that of a fully defined group of molecular-pathological entities for which safe and effective treatment is available. Hemophilia is likely to be the first widespread severe genetic condition to be cured by gene therapy in the third millennium. In the socio-economic arena it remains a challenge to humanity to know that four-fifths of the world's hemophiliacs still receive no treatment at all. Production of factor (F) VIII and IX in the milk of transgenic farmyard animals could provide a source of less expensive replacement therapy for developing countries. Affordable gene transfer will be the ultimate solution for hemophilia in the third world as in the first. Thus it may be confidently predicted that the early new millennium will see an end to this ancient scourge.