The present study describes the changes that have occurred in most Western countries, Brazil included, since medicine has shifted progressively from a paternalistic model to one that promotes patients autonomy and self-determination. Respect for patient autonomy and self-determination is the primary basis for withholding and withdrawing life support. An adult patient who has decision-making capacity and is appropriately informed has the right to forgo all forms of medical therapy, including life support measures. The right to refuse treatment applies equally to withholding therapy that might be offered, such as cardiopulmonary resuscitation, and to withdrawing therapy that is already underway, such as artificial hydration, nutrition, and ventilation. This right is based on the ethical principle of autonomy or self-determination. Helping an informed and capable patient to forgo life support under these circumstances is regarded as distinct from participating in requested homicide, assisted suicide, or passive/active euthanasia. The patient has the right to choose, including where the deathbed will be placed, and to be left alone with family at that time.