Human life is sacred and inviolable because God is its Creator and only He has the right to decide about the moment of its beginning and end. The right to life is fundamental human right, in which all other rights are justified. Human life and dignity that is inseparably linked with it are the basis of other goods inherent to man. That is why both The Holy Scripture and the documents of Magisterium of the Church indicate that the value of human life is incomparable to other goods and values. The Church feels obliged to defend the right to life from its beginning until its end and to maintain the requirements of Divine law as well as natural law in this aspect. Natural right to life is entirely protected by canon law, which states that homicide and any damage to human health is always a delict. A separate provision says that a person who procures a completed abortion incurs a latae sententiae excommunication (can. 1398). People have the right to do scientific research in order to develop their knowledge about the human organism and find solutions to problems that have troubled humankind for many years. However, it has to be said that some experiments can endanger a man and violate his right to life. That is why people should be ab le to distinguish between experiments carried to cure somebody or to save human life from the ones whose purpose is only scientific development. Nowadays in question are research and practices requiring use of human genome and also those which carry high risk for human life. In this context we should consider whether experiments connected to in vitro fertilisation, preimplantation genetic diagnosis and stem cells are morally accepted or should be prohibited because of the danger they cause, especially death of many human embryos. It has to be stated that the Church is not against all experiments but encourages and supports only those which in no way threaten life and the integrity of a person.