The Human Fertilisation and Embryology Act 1990 (HFE Act) has been described as a ‘milestone in biomedical regulation’. Yet as a milestone, it marks out the frontier of medical science as it stood at 1990. It was always accepted that the Act would not be the ‘last word on the subject’ of embryology. Five years on and, inevitably, the frontiers of the reproductive revolution have been pushed forward by scientific and clinical developments, and, again inevitably, those developments have thrown up new social, ethical and legal problems. Thanks to the passing of the 1990 Act, the new techniques do not exist in a vacuum: one of the achievements of the HFE Act is that it provides the institutional and legal framework in which new problems can be debated and resolved as they arise. The key element in that framework is the statutory licensing authority created by the 1990 Act-the Human Fertilisation and Embryology Authority (HFEA).