With development of new techniques for medical intervention, there has been a big dilemma for physicians about their decision when to stop treatment. Application of life-sustaining device sometimes results in a prolongation of painful period (dying process) for patients. Regarding the role of physician in the end-of-life decision, there could be two extremes : euthanasia vs. therapeutic tenacity (futility or accanimento terapeutico). Either extreme has its own limitations. One of possible solutions is an appropriate application of withholding and withdrawing interventions. However, several considerations are necessary for this. First, the clinical aspect of decision is whether a certain management is proportionate or non-proportionate for a given situation. If there is a chemotherapy regimen that has an efficacy of 15% partial response rate with side effects in the previous study, is it propotionate or non-proportionate treatment for advanced cancer patients? Other aspects of decision is regarding ethical, economical, and legal issues. One type of circumstances that may prompt claims of futility is the discrepancy between the values or goals of involved parties. Other concerns on futility issues are ① is it easy to break the bad news to dying patients in Korean culture? (communication problems at various levels) ② is social welfare system adequate enough not to interfere with a fair decision? Values on the issues like therapeutic decision and withholding life-sustaining treatments in terminally ill cancer patients are discordant between physicians and family members. To resolve controversies on the role of physicians as well as those of patients and their family members should be considered in the final decision.