AimsThe aim of this study was to identify the distinctive foundations of the care culture and how nurse leaders (NL) can manage and strengthen these in a quest for ethically sustainable caring cultures. BackgroundSustainability presupposes an ethical leadership, a management of the good care and a well-educated staff, but research on NLs as managers of ethically sustainable caring cultures is not available. DesignThe study has a quantitative design with elements of a qualitative research approach. MethodData were collected through a web-based questionnaire sent to staff at eight selected units at a hospital in western Finland during September 2013; the reply rate was 32%. The data material was comprised of opinion questions, the ranking of values and two open-ended questions on lodestars in care and ethical principles in care work. ResultsNLs manage a care culture that rests on a solid foundation, where staff are co-creators of an ethically sustainable caring culture that includes good traditions for the praxis of care. NLs as managers are therefore responsible for realizing and passing on ethically sustainable caring cultures and creating prerequisites for staff's growth and development. ConclusionThe basis of good care, patient safety and sustainability is comprised of ethics with a respectful and dignified care that is evidence-based and economically stable. Through their management NLs have a responsibility to nurture and protect the core of caring and create contextual, professional and cultural prerequisites to maintain the core and art of caring as well as care staff's ethical and professional competence.