Since the advent of test-tube babies, advances in the biomedical field have risen steadily. In parallel, the scientific body has never since ceased to debate the ethical issues that they arise. This is particularly the case regarding saviour-sibling. Saviour-sibling refers to a child who is conceived to cure an older brother or sister suffering from a serious family genetic disease. Therefore, it is meant to give birth to a child who will provide stem-cells taken from the umbilical cord or bone marrow afterwards, to treat an elder sick sibling. In England, this practice has been explicitly allowed by the new Human Fertilisation and Embryology Act 2008 under some strict conditions. In France, this practice, authorized by the Bioethics Law of August 2004 and confirmed by its decree of implementation published in the Official Journal on 23 December 2006, is also strictly regulated. This technique opens up new perspectives and enormous hope. Its legalisation is certainly justified by the suffering of the parents and to avoid that they travel to other States where it is permitted. However, it raises serious psychological ethical and judicial issues. Following an analysis of the English and French laws on saviour siblings, its controversial side will be highlighted, before concluding whether or not this new Pandora’s box which is saviour-sibling, should be closed and other alternative methods encouraged.