Experimentation with embryonic stem (ES) cells has become an important breakthrough in medical research. However, it is also a source of controversy, because it requires the destruction of the human embryos used to derive ES cells. This paper deals with some of the ethical issues concerning ES cell research. To begin with, the terms used in the debate on the ethical status of the human embryo need to be defined. Apart from the presumed benefits of ES cell research, we should also consider such issues as the strong opposition to this research by a large part of society, who argue in favour of protecting and respecting human embryos; the fragility and defenseless of human embryos; and the contradiction in terms inherent in the statement that human embryos must be treated with respect. Secondly, we should focus on possible conflicts between the financial, scientific, and ethical aspects of this debate. Thirdly, the significance of social and political debate requires clear and complete information that takes all consequences into account. Finally, the paper suggests how multipotent adult stem cell research may be an optimal and realistic alternative to ES cell research.