Background: The decision whether to initiate cardiopulmonary resuscitation may sometimes be ethically complex. While studies have addressed some of these issues, along with the role of nurses in cardiopulmonary resuscitation, most have not considered the importance of nurses acting as advocates for their patients with respect to cardiopulmonary resuscitation. Research objective: To explore what the nurse’s advocacy role is in cardiopulmonary resuscitation from the perspective of patients, relatives, and health professionals in the Basque Country (Spain). Research design: An exploratory critical (...) qualitative study was conducted from October 2015 to March 2016. Thematic analysis was used to analyse the data. Participants: Four discussion groups were held: one with patients and relatives (n = 8), two with nurses (n = 7 and n = 6, respectively), and one with physicians (n = 5). Ethical considerations: Approval was obtained from the Basque Country Clinical Research Ethics Committee. Findings: Three significant themes were identified: (a) accompanying patients during end of life in a context of medical dominance, (b) maintaining the pact of silence, and (c) yielding to legal uncertainty and concerns. Discussion: The values and beliefs of the actors involved, as well as pre-established social and institutional rules reduced nurses’ advocacy to that of intermediaries between the physician and the family within the hospital environment. On the contrary, in primary health care, nurses participated more actively within the interdisciplinary team. Conclusion: This study provides key information for the improvement and empowerment for ethical nursing practice in a cardiac arrest, and provides the perspective of patients and relatives, nurses and physicians. (shrink)