We know little about the trade-offs men make when considering the oncological and functional outcomes of individual treatment options for localised prostate cancer, and decisions are often influenced by physician opinion. The likely compromised functional results are viewed as a necessary means to gain survival benefit, but it is rare to look at what survival benefit patients may be willing to trade off to preserve functional status. In this well constructed discreet choice experiment (DCE), the COMPARE study provides an insight into individual choices. After a pilot study of the DCE on 106 patients, different tools were developed for low-intermediate and high-risk disease which were applied to 452 and 162 respondents, respectively. The study showed that men with low-intermediate risk disease are willing to accept 6.99% absolute decrease in survival to undergo active surveillance over definitive therapy, and up to 9.5% over 10 to 15 years in favour of preservation of urinary and sexual function. Men with both low-intermediate and high-risk disease were willing to trade a decrease in survival for faster physical recovery and improvements in sexual and urinary function with treatment. Both patient groups were willing to forego more percentage points of cancer specific survival to obtain an improvement in urinary function than in erectile function. It should be appreciated that abstract numerical percentages of survival are not intuitive to patients, but all men did prioritise quality of life as defined by multiple functional domains. The trade-off is probably greater if we consider disease progression after initial treatment and the effects of secondary treatments. This, and the three previous DCE studies referred to in this paper, will provide a valuable foundation for future development of dynamic decision aides for men with prostate cancer.