Little more than a decade ago, measurements of health-related quality of life (HRQOL) of prostate cancer patients began to enter the medical literature. Initially controversial and of little apparent relevance to clinical care, HRQOL has grown in importance in prostate cancer to the point that providing it in treatment discussions is now considered a core element of clinical care. The United States (US) Food and Drug Administration has used it to make approval decisions for prostate cancer drugs, and Europeans have endorsed its central role in prostate cancer as well [Altwein J, Ekman P, Barry M, et al. How is quality of life in prostate cancer patients influenced by modern treatment? The Wallenberg symposium. Urology 1997, 49(Suppl 4A), 66-76.]. We propose to characterise the treatment dilemmas facing patients with prostate cancer, the clinical relevance of HRQOL research, its central conceptual elements, the characteristics of some available instruments to measure it, the use of HRQOL in clinical studies, and some of the remaining challenges we have identified during our 13 years in the field.