The aim of prenatal screening programmes is stated in varying ways either to reduce number of children born with disabilities or to give pregnant mothers and couples reproductive choices. The principles and guidelines concerning genetic and prenatal screening have considered autonomy, voluntariness and informed decision-making as central principles for ethically acceptable screening programmes. Autonomy is one of the central principles of medical ethics, the other principles being non-maleficence, beneficence and justice. The chapter examines women's decision-making about Down's syndrome screening in three different EU countries: Finland, Greece and the Netherlands. It focuses on women's decision-making which is based on the information received and is connected to their experiences. Comparison of the three different countries revealed a big difference in the way serum screening is offered to women and in the respect for women's autonomy and right to make decisions concerning prenatal screening tests. A serious ethical problem exists concerning women's autonomy in prenatal screening.