BACKGROUND: The responsibility of obtaining organs for transplantation rests partly on critical care nurses. How nurses balance care of critically ill, brain-injured patients with the professional responsibility to procure organs is a question of ethical and clinical importance. OBJECTIVES: To describe the experiences of critical care nurses in making the shift from caring for a brain-injured patient identified as a potential organ donor to maintaining a brain-dead body. METHODS: An interpretive, phenomenological design was used. In 2 trauma centers, 9 critical care nurses were interviewed, and 2 of the 9 nurses were observed. RESULTS: Identification of potential organ donors is made under conditions of prognostic ambiguity. The transition from brain injury to brain death is a period of instability in which the critical care team must decide quickly whether to resuscitate a patient in order to procure organs. After a patient is brain dead, critical care nurses' relationship with and responsibility toward the patient change. CONCLUSIONS: The process of identifying potential organ donors and holding open the tentative possibility of organ procurement illustrates the practical difficulties of early referral of potential donors to organ procurement organizations. Early referral to an organ procurement organization implies a commitment to organ procurement that some nurses may hesitate to make because such a commitment changes their relationship with a brain-injured patient.