Background: Organ donation and transplantation represent one of the most important scientific advances over the last decades. Due to the complexity of these procedures and related ethical–legal aspects, however, there are a lot of doubts and uncertainty about the brain death diagnosis and the maintenance of potential organ donor. Aim: To identify and discuss the different meanings and experiences of registered nurses and physicians from an adult intensive care unit in relation to the diagnosis of brain death and the maintenance (...) of potential organ donors for transplantation purposes. Study Design: Participants were registered nurses and physicians from an adult intensive care unit at a University Hospital from Brazil. Data were collected through semi-structured interviews and analyzed using content analysis. Ethical considerations: This study was approved by the University of São Paulo at Ribeirão Preto College of Nursing Research Ethics Committee. Results: Two main categories emerged from the analysis: brain death diagnosis and its implications and maintenance of the potential organ donor and its repercussion in the donation–transplantation process. Six subcategories were also identified: understanding the brain death diagnosis as a tool to aid decision-making; diagnosis as guarantee of rights; difficulties encountered to establish the diagnosis; clinical criteria adopted in Brazil and related ethical–legal aspects; specificities of care to the brain dead person and outcomes; and nurse’s duties toward the brain dead person. Conclusion: Although the brain death diagnosis is scientifically and legally defined in Brazil and the maintenance of the potential organ donor for transplantation purposes has been addressed during the last years, there are still some doubts about the subject, as its understanding varies according to the personal beliefs, culture, and educational background of individuals, including those who work in this scenario. (shrink)