Since 1974, when the first policies about ‘do not attempt resuscitation’ orders were published [1], the decision not to resuscitate patients in cardiac arrest has been a controversial issue in medical practice. For this reason, the ‘do not attempt resuscitation’ order is, perhaps, the directive and the decision to withhold medical treatment with the widest bibliography. In this review, in accordance with the 2000 Guidelines for Cardiopulmonary Resuscitation [2], I will use the term ‘do not attempt resuscitation (DNAR)’ instead of the more popular ‘do not resuscitate (DNR)’. The first sentence indicates more clearly the decision to take, because the success of a resuscitation is not always guaranteed.