Bioethics is an interdisciplinary science that deals with the moral aspects of medicine, biotechnology and the value of life in general. Quality of life concept is the basis for one of the models of bioethics. Its supporters understand the value of human life by relying on the categories of its qualitative characteristics. They argue that the value of life is relative and depends on certain criteria, and prove the permissibility to terminate it in some cases. Quality of life conception is criticized, above all, by those scholars who rely on religious ideas of the equal value and inviolability of all people’s lives. This article reveals several examples of such criticism in the works of Polish and American authors: T. Biesaga, H. Ciach, G. Hołub, P. Kieniewicz, R. P. George and P. Lee. Citing the arguments of that Christian thinkers, the author forms her own attitude to the problem. The ethical and ontological sources of quality of life concept, namely utilitarianism and naturalism, become the main object of criticism. It is significant that in the utilitarian appeal to maximize happiness as pleasure and calculate the gain or loss they see an attempt to establish the primacy of the overall well-being over an individual’s life as well as a reason for killing those individuals whose lives do not meet quality criteria and impair overall well-being. They also criticize such a consequence of the naturalistic view as reduction of the personality to its manifestations. The absence of such manifestations becomes for the supporters of the quality of life concept the basis for conclusion about a low quality of life of some individuals. One more critical remark towards the quality of life concept concern erasing of differences between humans and animals and their interests. The technocratic attitude that permits any manipulations of a human life if only they can be performed is criticized too. The author demonstrates that the fundamental fault of the quality of life concept which is criticized by all its opponents is a limited understanding of human nature and human life.