In the last two decades, the term “quality-of-life” has become popular in medicine and health care. There are, however, important differences in the meaning and the use of the term. The message of all quality-of-life talk is that medicine and health care are not valuable in themselves. They are valuable to the extent that they contribute to the quality of life of patients. The ultimate aims of medicine and health care are not health or prolongation of life as such, but (...) preservation or improvement of the quality of life. The primary aims of medicine and health care, such as the prolongation of life, can – but need not always – come into conflict with the ultimate ones: medical treatments do not always benefit a patient. In this article I will, first, summarize the results of my explorations of the use and the meaning of the term “quality-of-life.” The use and the meaning of the term turn out to depend on the contexts of medical decisionmaking in which it is used. I will show that there are at least three different concepts of quality-of-life. Second, I will argue that the different concepts of quality-of-life are not unrelated. They point to different components of and/or conditions for happiness. Third, I will analyze the relation between the three concepts of qualityof-life, health and happiness. (shrink)